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Kinematics

Practice exam-style IB Math AI questions for Kinematics, aligned with the syllabus and grouped by topic.

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Verified by Karim
Paper
Difficulty
Status
Level
Question 1
HL • Paper 1
Easy
Calculator Permitted
HL • Paper 1
Easy
Calculator Permitted

A particle moves along a straight line. Its displacement ss metres from the origin at time tt seconds is given by

s(t)=t36t2+9t+2,t0s(t)=t^3-6t^2+9t+2, \qquad t\geq 0
A

Find expressions for the velocity v(t)v(t) and acceleration a(t)a(t) of the particle.

[2]
B

Find the times at which the particle is instantaneously at rest.

[2]
C

Find the acceleration of the particle at the first instant when it is at rest.

[1]
Question 2
HL • Paper 1
Easy
Calculator Permitted
HL • Paper 1
Easy
Calculator Permitted

The acceleration of a moving object is a(t)=6t4 m s2a(t)=6t-4\ \text{m s}^{-2}. Initially, its velocity is 3 m s13\ \text{m s}^{-1} and its displacement is 2 m-2\ \text{m}.

A

Find an expression for the velocity v(t)v(t).

[2]
B

Find an expression for the displacement s(t)s(t).

[2]
C

Find the displacement of the object after 22 seconds.

[1]
Question 3
HL • Paper 1
Easy
Calculator Permitted
HL • Paper 1
Easy
Calculator Permitted

The position of an object moving along a straight line is modelled by

x=5cos(0.4t)2x=5\cos(0.4t)-2

where xx is measured in metres and tt in seconds.

A

Find x˙\dot{x} and x¨\ddot{x}.

[3]
B

Find the first time after t=0t=0 when the object is instantaneously at rest.

[2]
Question 4
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

The velocity-time graph of a cyclist is formed by straight-line segments joining the points (0,2)(0,2), (2,6)(2,6), (5,0)(5,0), (7,4)(7,-4) and (9,0)(9,0), where time is measured in seconds and velocity in m s1\text{m s}^{-1}.

Velocity-time graph of a cyclist with straight-line segments joining the given points, including portions above and below the time axis.
A

Find the cyclist's acceleration during the first 22 seconds.

[2]
B

Find the cyclist's displacement during the 99 seconds.

[2]
C

Find the total distance travelled during the 99 seconds.

[2]
Question 5
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

The velocity of a delivery robot moving along a straight corridor is given by

v(t)={4t,0t6,t8,6<t10,v(t)= \begin{cases} 4-t, & 0\leq t\leq 6,\\ t-8, & 6<t\leq 10, \end{cases}

where vv is measured in m s1\text{m s}^{-1}.

A

Find the times at which the robot changes direction.

[2]
B

Find the displacement of the robot during the first 1010 seconds.

[2]
C

Find the total distance travelled during the first 1010 seconds.

[2]
Question 6
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

An object has initial velocity 2 m s1-2\ \text{m s}^{-1}. Its acceleration is

a(t)={2,0t3,1,3<t7.a(t)= \begin{cases} 2, & 0\leq t\leq 3,\\ -1, & 3<t\leq 7. \end{cases}
A

Find the velocity of the object at t=3t=3 and at t=7t=7.

[2]
B

Find the displacement of the object from t=0t=0 to t=7t=7.

[2]
C

Determine when the object changes direction for 0<t<70<t<7.

[2]
Question 7
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

The velocity of a particle moving along a straight line is

v(t)=t25t+4,0t5v(t)=t^2-5t+4, \qquad 0\leq t\leq 5

where vv is measured in m s1\text{m s}^{-1}.

A

Find the times at which the particle changes direction.

[2]
B

Find the displacement of the particle during the first 55 seconds.

[2]
C

Find the total distance travelled by the particle during the first 55 seconds.

[3]
Question 8
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

A particle moves in the positive direction along a straight line. Its velocity v m s1v\ \text{m s}^{-1} is related to its displacement s ms\ \text{m} by

v=16s,0s<16v=\sqrt{16-s}, \qquad 0\leq s<16

At t=0t=0, the particle is at s=0s=0.

A

Find the acceleration of the particle.

[2]
B

Find the speed of the particle when s=7s=7.

[1]
C

Find the time taken for the particle to travel from s=0s=0 to s=7s=7.

[2]
Question 9
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

A particle moves along a straight line with velocity

v(t)=12tet,t0v(t)=12te^{-t}, \qquad t\geq 0

where vv is measured in m s1\text{m s}^{-1}.

A

Find an expression for the acceleration of the particle.

[2]
B

Find the time at which the velocity is greatest and state this greatest velocity.

[2]
C

Find the exact distance travelled during the first 22 seconds.

[2]
Question 10
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

A particle starts at the origin and moves along a straight line with velocity

v(t)=3t212t+9,t0v(t)=3t^2-12t+9, \qquad t\geq 0
A

Determine the first time after t=0t=0 when the particle returns to the origin.

[2]
B

Find the total distance travelled before the particle first returns to the origin.

[3]
Question 11
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

The velocity of a particle is

v(t)=t(t3)2,0t5v(t)=t(t-3)^2, \qquad 0\leq t\leq 5
A

Find an expression for the acceleration of the particle.

[1]
B

Determine the intervals during which the particle is speeding up.

[3]
C

Explain why the particle does not change direction at t=3t=3.

[1]
Question 12
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

The displacement of a particle from an origin is

s(t)=t36t2+9t,0t3.5s(t)=t^3-6t^2+9t, \qquad 0\leq t\leq 3.5

where ss is measured in metres.

A

Find the times in the interval when the particle is instantaneously at rest.

[2]
B

Find the greatest displacement of the particle from the origin during the interval.

[2]
C

Find the total distance travelled during the interval.

[2]
Question 13
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

A particle moves along a straight line with velocity

v(t)=t2kt+3,t0v(t)=t^2-kt+3, \qquad t\geq0

where tt is measured in seconds and v(t)v(t) is measured in m s1\text{m s}^{-1}; the polynomial uses the numerical value of tt, and kk is a dimensionless constant. The particle changes direction at t=1t=1.

A

Find the value of kk.

[2]
B

Find the other time at which the particle changes direction.

[1]
C

Find the total distance travelled during the first 44 seconds.

[2]
Question 14
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

The displacement of a buoy moving vertically is modelled by

s(t)=20sin(0.15t),0t30s(t)=20\sin(0.15t), \qquad 0\leq t\leq30

where ss is measured in metres and tt in seconds.

A

Find expressions for the velocity and acceleration of the buoy.

[2]
B

Find the first time after t=0t=0 when the buoy is instantaneously at rest.

[2]
C

Find the total distance travelled by the buoy during the 3030 seconds.

[2]
Question 15
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

A train moves along a straight track. Its acceleration a m s2a\ \text{m s}^{-2} depends on its displacement s ms\ \text{m} according to

a=0.4sa=-0.4s

When s=0s=0, its speed is 6 m s16\ \text{m s}^{-1} and it is moving in the positive direction.

A

Show that the speed vv satisfies v2=360.4s2v^2=36-0.4s^2.

[3]
B

Hence find the displacement at which the train first comes to rest.

[2]
Question 16
HL • Paper 1
Medium
Calculator Permitted
HL • Paper 1
Medium
Calculator Permitted

A particle moves along a straight line with velocity

v(t)=(t2)2(t5),0t6v(t)=(t-2)^2(t-5), \qquad 0\leq t\leq6

Here, tt is measured in seconds and v(t)v(t) is measured in m s1\text{m s}^{-1}.

A

Find all the times at which the particle is instantaneously at rest.

[2]
B

Determine which of these times corresponds to a change of direction. Justify your answer.

[2]
C

Find the total distance travelled by the particle during the 66 seconds.

[3]
Question 17
HL • Paper 2
Medium
Calculator Permitted
HL • Paper 2
Medium
Calculator Permitted

A shuttle moves along a straight track. Its velocity at time tt seconds is given by

v(t)=4cos(πt4),0t8v(t)=4\cos\left(\frac{\pi t}{4}\right),\qquad 0\leq t\leq 8

where velocity is measured in m s1\text{m s}^{-1}. Initially, the shuttle is 33 metres from an origin OO. Take the positive direction to be away from OO, and let s(t)s(t) be the signed position relative to OO, so that s(0)=3 ms(0)=3\ \text{m}.

A
I.

Find an expression for the acceleration of the shuttle.

[2]
II.

Determine the times at which the shuttle changes direction.

[2]
B

Find the total distance travelled and the greatest displacement of the shuttle from OO during the interval.

[4]
Question 18
HL • Paper 2
Medium
Calculator Permitted
HL • Paper 2
Medium
Calculator Permitted

A cart moves along a straight test track with acceleration

a(t)=6t6a(t)=6t-6

where t0t\geq0. At t=0t=0, its velocity is 4 m s14\ \text{m s}^{-1} and its displacement is 3 m-3\ \text{m}.

A
I.

Find the velocity of the cart at time tt.

[2]
II.

Find the displacement of the cart at time tt.

[2]
B

Determine the minimum speed of the cart during the first 33 seconds and the total distance it travels during this interval.

[4]
Question 19
HL • Paper 2
Medium
Calculator Permitted
HL • Paper 2
Medium
Calculator Permitted

Two automated carts, AA and BB, move along the same straight rail. Their displacements from an origin at time tt seconds are

sA=t2+2t,sB=304ts_A=t^2+2t,\qquad s_B=30-4t

where displacement is measured in metres.

A
I.

Find the velocity and acceleration of each cart.

[2]
II.

Find the first time at which the carts meet.

[2]
B

Find the total distance travelled by the two carts before they meet and their relative speed at the meeting time.

[4]
Question 20
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

A drone moves horizontally in the positive direction. Its velocity v m s1v\ \text{m s}^{-1} is related to its displacement s ms\ \text{m} by

v=10s+2,s0v=\frac{10}{s+2},\qquad s\geq0

At t=0t=0, the drone is at s=0s=0.

A
I.

Using a=vdvdsa=v\dfrac{dv}{ds}, find the acceleration in terms of ss.

[2]
II.

Find the acceleration when s=3s=3.

[2]
B

Find the time taken for the drone to reach s=8s=8 and its average speed during this journey.

[4]
Question 21
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

The horizontal position of a sensor attached to a machine is modelled by

x(t)=6e0.2tcost,t0x(t)=6e^{-0.2t}\cos t,\qquad t\geq0

where xx is measured in metres and tt in seconds.

A
I.

Find x˙\dot{x}.

[2]
II.

Find x¨\ddot{x}.

[2]
B

Determine the first time after t=0t=0 when the sensor is instantaneously at rest. Find its position and state whether this position is a local maximum or a local minimum.

[4]
Question 22
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

An elevator moves vertically, with upward taken as positive. Its velocity is

v(t)=(t1)(t3),0t5v(t)=(t-1)(t-3),\qquad 0\leq t\leq5

where velocity is measured in m s1\text{m s}^{-1}. At t=0t=0, the elevator is 44 metres above a reference level.

A
I.

Find the acceleration and the times when the elevator changes direction.

[2]
II.

Find the elevator's displacement from the reference level at t=5t=5.

[2]
B

Find the total distance travelled by the elevator and its greatest height above the reference level during the interval.

[4]
Question 23
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

A particle has acceleration

a(t)=3sin(πt3),0t6a(t)=3\sin\left(\frac{\pi t}{3}\right),\qquad 0\leq t\leq6

Initially, its velocity is 9π m s1-\dfrac{9}{\pi}\ \text{m s}^{-1} and its displacement is 1010 metres.

A
I.

Find an expression for the velocity.

[2]
II.

Determine the times when the particle changes direction.

[2]
B

Find the total distance travelled and the greatest displacement from the origin during the interval.

[4]
Question 24
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

Two runners, AA and BB, move in the positive direction along a straight path. At t=0t=0, runner AA is at the origin and runner BB is 99 metres ahead. Runner AA has velocity vA=2t m s1v_A=2t\ \text{m s}^{-1}, while runner BB runs at a constant velocity of 6 m s16\ \text{m s}^{-1}.

A
I.

Find expressions for the displacement of each runner from the origin.

[2]
II.

Find the time when runner AA first catches runner BB.

[2]
B

After runner AA passes runner BB, determine when the runners are first 2020 metres apart. Find their relative speed at this time.

[4]
Question 25
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A camera drone moves along a straight tunnel. Its displacement from the tunnel entrance is modelled by

s(t)=0.05t30.9t2+4ts(t)=0.05t^3-0.9t^2+4t

where ss is measured in metres, tt is measured in seconds and 0t120\leq t\leq12.

A

Consider the velocity and direction of motion of the drone.

I.

Find an expression for the velocity of the drone.

[2]
II.

Determine the times at which the drone changes direction.

[2]
B

Find the displacement of the drone from its starting point after 1212 seconds.

[2]
C

Hence find the total distance travelled by the drone during the 1212 seconds.

[2]
Question 26
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

The velocity of a ferry moving towards and away from a terminal is modelled by

v(t)=3sin(πt6)1v(t)=3\sin\left(\frac{\pi t}{6}\right)-1

where vv is measured in m s1\text{m s}^{-1} and 0t120\leq t\leq12. Positive velocity represents motion towards the terminal.

Velocity-time graph of a ferry approaching and leaving a terminal over 0 to 12 s.
A

Consider the intersections of the velocity graph with the time axis.

I.

Find the two times at which the ferry is instantaneously at rest.

[2]
II.

State the interval during which the ferry moves towards the terminal.

[2]
B

Find the net displacement of the ferry over the 1212 seconds and interpret its sign.

[2]
C

Find the total distance travelled by the ferry during the 1212 seconds.

[2]
Question 27
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

The velocity of an experimental racing vehicle is modelled by

v(t)=t(12t)e0.1t,0t12v(t)=t(12-t)e^{-0.1t},\qquad 0\leq t\leq12

where vv is measured in m s1\text{m s}^{-1}.

A

Consider the acceleration of the vehicle.

I.

Show that

a(t)=e0.1t(123.2t+0.1t2)a(t)=e^{-0.1t}(12-3.2t+0.1t^2)
[2]
II.

Find the time at which the vehicle reaches its greatest velocity.

[2]
B

Find the greatest velocity of the vehicle.

[2]
C

Find the total distance travelled during the 1212 seconds.

[2]
Question 28
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A ball is projected vertically upwards from a platform. Taking upwards as positive, its acceleration is modelled by

a(t)=9.80.4ta(t)=-9.8-0.4t

Initially, the ball has velocity 18 m s118\ \text{m s}^{-1} and displacement s=0s=0.

A

Find the velocity and displacement models.

I.

Find v(t)v(t).

[2]
II.

Find s(t)s(t).

[2]
B

Find the greatest height reached above the platform.

[2]
C

Find the speed of the ball when it first returns to the level of the platform.

[2]
Question 29
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

The velocity of a solar-powered cart was recorded during a test. A quadratic regression model is to be used for the data.

t [s]

v [m s^-1]

0

1

2

5

4

7.4

6

8.2

8

7.4

10

5

A

Use the velocity data to construct and analyze a quadratic model.

I.

Find the quadratic regression equation in the form v=at2+bt+cv=at^2+bt+c.

[2]
II.

Use the model to find the maximum velocity and the time at which it occurs.

[2]
B

Assuming the model continues to apply, find the first time after t=10t=10 at which the cart comes to rest and the total distance travelled by then.

[2]
C

Give one reason why the stopping prediction in part (b) should be treated with caution.

[2]
Question 30
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

A particle moves along a straight line with velocity

v(t)=t36t2+8tv(t)=t^3-6t^2+8t

for 0t50\leq t\leq5. Initially, its displacement from an origin is 22 metres.

A
I.

Find the acceleration and the times when the particle is instantaneously at rest.

[2]
II.

Determine the intervals during which the particle is speeding up.

[2]
B

Find the total distance travelled and the greatest displacement from the origin during the interval.

[4]
Question 31
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

A particle starts at an origin and moves along a straight line. Its velocity is modelled by

v(t)=Aet1v(t)=Ae^{-t}-1

where A>0A>0. The particle first comes to rest at t=ln4t=\ln4.
Here, tt is the numerical time in seconds, v(t)v(t) and AA are measured in m s1\text{m s}^{-1}, and displacement is measured in metres.

A
I.

Find the value of AA.

[2]
II.

Find the acceleration at t=ln4t=\ln4 and explain why the particle changes direction at this time.

[2]
B

Determine the first time after t=0t=0 when the particle returns to the origin and find the total distance travelled by then.

[4]
Question 32
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

The velocity of a maintenance vehicle is modelled by

v(t)=2+3sint,0t2πv(t)=2+3\sin t,\qquad 0\leq t\leq2\pi

where vv is measured in m s1\text{m s}^{-1}. The vehicle starts at displacement s=1 ms=-1\ \text{m}.

Velocity-time graph of v = 2 + 3 sin t on 0 2 t 2 2.
A
I.

Find the two times when the vehicle is instantaneously at rest.

[2]
II.

State the direction of motion on each of the three resulting time intervals.

[2]
B

Find the net displacement and the total distance travelled during the interval.

[4]
Question 33
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

A particle moves along a straight line with velocity

v(t)=tet/2(6t),0t10v(t)=te^{-t/2}(6-t),\qquad 0\leq t\leq10

where tt is measured in seconds and v(t)v(t) is measured in metres per second.

A
I.

Find the acceleration of the particle.

[2]
II.

Determine when the particle changes direction.

[2]
B

Find the maximum speed and the total distance travelled during the interval.

[4]
Question 34
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

A boat moves along a straight channel. Its acceleration is

a(t)={2t,0t2,2,2<t6,a(t)=\begin{cases}2t,&0\leq t\leq2,\\-2,&2<t\leq6,\end{cases}

where acceleration is measured in m s2\text{m s}^{-2}. Initially, the boat's velocity is 1 m s1-1\ \text{m s}^{-1}.

A
I.

Find a piecewise expression for the velocity.

[2]
II.

Determine the times when the boat changes direction.

[2]
B

Find the displacement and the total distance travelled during the first 66 seconds.

[4]
Question 35
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

The position of a robotic arm along a straight guide is modelled by

x(t)=t+4sint,0t2πx(t)=t+4\sin t,\qquad 0\leq t\leq2\pi

where tt is measured in seconds, angles are in radians, and xx is measured in metres.

A
I.

Find the velocity and acceleration.

[2]
II.

Find the times at which the position is stationary and classify each stationary position.

[2]
B

Find the total distance travelled by the robotic arm during the interval.

[4]
Question 36
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

A capsule moves in the positive direction along a straight tunnel. Its speed v m s1v\ \text{m s}^{-1} and displacement s ms\ \text{m} satisfy

v2=36+4ss2v^2=36+4s-s^2

Initially, s=0s=0.

A
I.

Show that the acceleration is a=2sa=2-s.

[2]
II.

Find the displacement at which the speed is greatest and state this greatest speed.

[2]
B

Determine the displacement at which the capsule first comes to rest and the time taken to reach this displacement.

[4]
Question 37
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A test vehicle moves in the positive direction along a straight track. Its acceleration depends on its displacement ss according to

a=60.5sa=6-0.5s

At s=0s=0, the vehicle has speed 2 m s12\ \text{m s}^{-1}.

A

Use the relationship between acceleration, velocity and displacement.

I.

Show that the velocity satisfies v2=4+12s0.5s2v^2=4+12s-0.5s^2.

[2]
II.

Find the greatest speed attained before the vehicle first comes to rest.

[2]
B

Find the displacement at which the vehicle first comes to rest.

[2]
C

Find the time taken for the vehicle to reach this displacement.

[2]
Question 38
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

During a braking test, the acceleration aa of a car is related to its velocity vv by

a=0.04v2a=-0.04v^2

At t=0t=0, the car passes a marker with velocity 20 m s120\ \text{m s}^{-1} and displacement s=0s=0.

A

Consider the velocity and displacement during braking.

I.

Verify that v(t)=201+0.8tv(t)=\frac{20}{1+0.8t} satisfies the acceleration model and the initial condition.

[2]
II.

Find an expression for s(t)s(t).

[2]
B

Safety regulations define the car as effectively stopped when its speed first reaches 2 m s12\ \text{m s}^{-1}. Find the distance travelled by this time.

[2]
C

Explain why the model does not predict a finite time at which the car is completely at rest.

[2]
Question 39
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A capsule moves along a straight evacuation tube. Its velocity depends on its displacement according to

v=6e0.03s,s0v=6e^{-0.03s},\qquad s\geq0

where ss is measured in metres and vv in m s1\text{m s}^{-1}.

A

Consider the capsule's acceleration and travel time.

I.

Show that the acceleration is a=0.03v2a=-0.03v^2.

[2]
II.

Find the time taken to travel the first 4040 metres.

[2]
B

Find the displacement at which the speed is half its initial value.

[2]
C

The speed is to fall to a fraction qq, where 0<q<10<q<1, of its initial value. Obtain an expression for the required displacement and explain how it changes as qq decreases.

[2]
Question 40
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

An elevator undergoes a six-second acceleration phase. Its acceleration is modelled by

a(t)=kt(6t),0t6a(t)=kt(6-t),\qquad 0\leq t\leq6

The elevator starts from rest and has velocity 12 m s112\ \text{m s}^{-1} at t=6t=6.

A

Determine the parameter and the resulting velocity.

I.

Find the value of kk.

[2]
II.

Find an expression for v(t)v(t).

[2]
B

Find the distance travelled during the acceleration phase.

[2]
C

For a general acceleration phase of duration TT, where T>0T>0, suppose a(t)=kt(Tt)a(t)=kt(T-t), the elevator starts from rest and reaches velocity V>0V>0 at time TT. Show that the distance travelled is VT2\frac{VT}{2}.

[2]
Question 41
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A magnetic transport pod moves in the positive direction. Its acceleration depends on its displacement according to

a=2s+1,s0a=\frac{2}{s+1},\qquad s\geq0

At s=0s=0, its speed is 1 m s11\ \text{m s}^{-1}.

A

Use a=vdvdsa=v\frac{dv}{ds} to investigate the motion.

I.

Show that v2=1+4ln(s+1)v^2=1+4\ln(s+1).

[2]
II.

Find the speed when s=9s=9.

[2]
B

Find the displacement at which the pod first reaches a speed of 5 m s15\ \text{m s}^{-1}.

[2]
C

Explain how the pod can continue to speed up even though its acceleration decreases as ss increases.

[2]
Question 42
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A maintenance shuttle moves along a straight rail. Its acceleration during an eight-second control cycle is

a(t)=3sin(πt8),0t8a(t)=3\sin\left(\frac{\pi t}{8}\right),\qquad 0\leq t\leq8

Initially, its velocity is 2 m s1-2\ \text{m s}^{-1} and its displacement is zero.

Acceleration-time graph over one 8 s control cycle.
A

Find the velocity and the reversal time.

I.

Find an expression for v(t)v(t).

[2]
II.

Find the time at which the shuttle changes direction.

[2]
B

Find the displacement of the shuttle during the control cycle.

[2]
C

Find the total distance travelled during the control cycle.

[2]
Question 43
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A robotic cart has velocity

v(t)=t2kt+6v(t)=t^2-kt+6

where t0t\geq0 is the numerical time in seconds, v(t)v(t) is measured in m s1\text{m s}^{-1}, and kk is a positive numerical constant.

A

First consider the case k=5k=5.

I.

Find the times at which the cart changes direction.

[2]
II.

Find the total distance travelled during the first 55 seconds.

[2]
B

Determine the value of kk for which the cart is instantaneously at rest once but does not change direction.

[2]
C

Deduce the range of values of kk for which the cart changes direction twice for t>0t>0.

[2]
Question 44
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A delivery pod travels along a straight underground route. Its velocity is modelled by

v(t)=1+5cos(πt10),0t20v(t)=1+5\cos\left(\frac{\pi t}{10}\right),\qquad 0\leq t\leq20

where vv is measured in m s1\text{m s}^{-1}.

Velocity-time graph of the delivery pod over 0–20 s.
A

Consider the direction of travel of the pod.

I.

Find the times at which the pod changes direction.

[2]
II.

Find the proportion of the 2020 seconds during which the pod moves in the positive direction.

[2]
B

Find the displacement of the pod during the 2020 seconds.

[2]
C

Find the total distance travelled during the 2020 seconds.

[2]
Question 45
HL • Paper 2
Hard
Calculator Permitted
HL • Paper 2
Hard
Calculator Permitted

A vehicle moves along a straight road in the positive direction. During braking, its acceleration depends on its displacement ss from the point where braking begins according to

a=10.05sa=-1-0.05s

At s=0s=0, the vehicle's speed is 12 m s112\ \text{m s}^{-1}.

A
I.

Show that the speed satisfies v2=1442s0.05s2v^2=144-2s-0.05s^2.

[2]
II.

Find the stopping distance and the magnitude of the acceleration when the vehicle stops.

[2]
B

Find the time taken for the vehicle to stop.

[4]
Question 46
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

Two autonomous vehicles, AA and BB, move along the same straight test track. At t=0t=0, vehicle AA is at the origin and vehicle BB is DD metres ahead. Their velocities are

vA(t)=6+2sin(0.5t),vB(t)=4+0.3tv_A(t)=6+2\sin(0.5t),\qquad v_B(t)=4+0.3t

Initially, both vehicles move in the positive direction.

A

For part (a)(i), leave the initial separation as DD. For part (a)(ii), take D=12D=12 m.

I.

Find expressions for the positions sA(t)s_A(t) and sB(t)s_B(t).

[2]
II.

Find the first time at which AA catches BB.

[2]
B

For this part, take D=12D=12 m. Find the velocity of each vehicle at the first meeting and state which vehicle is moving faster.

[2]
C

The initial separation is changed from 1212 metres to DD metres. Find the greatest value of DD for which AA catches BB at least once.

[2]
Question 47
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A carriage moves in the positive direction along a straight track. Its velocity is related to its displacement by

v=(s+4)(20s),0s20v=\sqrt{(s+4)(20-s)},\qquad 0\leq s\leq20

where ss is measured in metres.

A

Investigate the acceleration and speed of the carriage.

I.

Show that the acceleration is a=8sa=8-s.

[2]
II.

Find the maximum speed of the carriage.

[2]
B

Find the time taken for the carriage to travel from s=0s=0 to s=20s=20.

[2]
C

Determine whether the carriage spends more time accelerating or decelerating before reaching s=20s=20. Justify your answer.

[2]
Question 48
HL • Paper 3
Hard
Calculator Permitted
HL • Paper 3
Hard
Calculator Permitted

A moving platform has velocity

v(t)=2+4costv(t)=2+4\cos t

where vv is measured in m s1\text{m s}^{-1} and tt is measured in seconds. The argument of the cosine is in radians, and over one period 0t2π s0\leq t\leq2\pi\ \text{s}.

Velocity-time graph for one period of v(t)=2+4 cos t.
A

Consider the platform's motion over one period.

I.

Find the times at which the platform changes direction.

[2]
II.

Find the displacement over one period.

[2]
B

Find the exact total distance travelled during the period.

[2]
C

A general platform has velocity v(t)=c+Bcostv(t)=c+B\cos t, where 0<c<B0<c<B. Let θ=cos1(cB)\theta=\cos^{-1}\left(-\frac{c}{B}\right). Show that its total distance over one period is

4cθ2πc+4Bsinθ4c\theta-2\pi c+4B\sin\theta
[2]

Integration