A book rests on a horizontal table. What is the Newton's third law partner of the gravitational force exerted by Earth on the book?

A block of mass 4.0 kg is pulled at constant speed across a horizontal surface. The coefficient of dynamic friction is 0.25. What is the frictional force on the block?

A spring obeys Hooke's law. A force of 6.0 N produces an extension of 3.0 cm. What is the spring constant?

Two carts collide on a horizontal air track and stick together. The track is effectively frictionless. What is conserved during the collision?

A lamp hangs at rest from a vertical cable.

A 0.060 kg tennis ball approaches a racket at 20 m s⁻¹ and leaves in the opposite direction at 30 m s⁻¹. What is the magnitude of the impulse on the ball?

A point on a wheel of radius 0.40 m rotates with angular velocity 12 rad s⁻¹. What is its linear speed?

A stone moves at constant speed in a horizontal circle on a string. Why does the tension do no work on the stone?

A moving puck collides with a stationary puck on a frictionless air table. For analysing the collision in two dimensions, what condition must be applied?

A 2.5 kg trolley is pulled horizontally by a 7.0 N force. A frictional force of 2.0 N acts in the opposite direction.

A small steel sphere falls vertically through oil and reaches terminal velocity.

A cube of volume $1.8 imes10^{-4}\, ext{m}^3$ is fully submerged in water of density $1000\, ext{kg m}^{-3}$.

A 0.15 kg ball moves in a horizontal circle of radius 0.60 m at a constant speed of 4.0 m s⁻¹.

In a demonstration, two identical pucks collide elastically on a horizontal air table. One puck is initially stationary.

A student investigates a spring by hanging different loads and measuring extension.

Two dynamics carts collide and stick together. Motion sensors record the velocity of the carts before and after the collision.

A car travels around a flat circular bend of radius 50 m. The coefficient of static friction between the tyres and road is 0.72. What is the maximum speed before skidding?

A 0.20 kg puck moving east at 4.0 m s⁻¹ collides with another puck. After the collision it moves at 3.0 m s⁻¹ at 30° north of east. What is the northward component of its final momentum?

An object initially at rest explodes into two fragments. One fragment has momentum 6.0 kg m s⁻¹ east. What is the momentum of the other fragment if external forces are negligible?

Two identical smooth pucks collide elastically on a frictionless table. One puck is initially stationary. The collision is not head-on. What is the angle between the two final velocity directions?

A particle initially moving along the x-axis breaks into two fragments. Fragment 1 has a positive y-component of momentum after the explosion. What must be true of the y-component of momentum of fragment 2?

A 0.50 kg object moving north at 8.0 m s⁻¹ splits into two fragments. The total eastward momentum of one fragment is 1.5 kg m s⁻¹. What is the eastward momentum of the other fragment?

In the kinetic model of an ideal gas, which assumption about molecular collisions allows pressure to be modelled using momentum changes without loss of kinetic energy?

A collision on a frictionless table has total initial momentum 0.60 kg m s⁻¹ in the x-direction and zero in the y-direction. After the collision, object 1 has momentum components (0.20, 0.30) kg m s⁻¹. What are the momentum components of object 2?

A rocket ejects exhaust gases at a relative speed of $2.4 imes10^3\, ext{m s}^{-1}$. The mass ejection rate is $15\, ext{kg s}^{-1}$.

A 0.80 kg cart moving at 1.5 m s⁻¹ collides with a stationary 1.2 kg cart. The carts stick together.

A bucket of water is swung in a vertical circle at constant speed.

A 0.30 kg puck moving initially east at 5.0 m s⁻¹ collides with another puck. After the collision, the 0.30 kg puck moves at 4.0 m s⁻¹ at 25° north of east.

An object initially at rest explodes into two fragments. Fragment A has mass 0.40 kg and moves at 6.0 m s⁻¹ east. Fragment B has mass 0.60 kg.

A ball of mass 0.20 kg travelling along the x-axis at 12 m s⁻¹ strikes a stationary ball of mass 0.30 kg. After the collision, the 0.20 kg ball moves at 8.0 m s⁻¹ at 40° above the x-axis.

A gas molecule collides elastically with a rigid wall.

The force on a ball during contact with a bat is measured using a force sensor.

A steel sphere is dropped through different liquids. The terminal speed is measured and the viscosity is calculated using Stokes' law.

A bung is rotated in a horizontal circle. The radius is varied while the same hanging mass supplies the tension. The speed is found from timing several revolutions.

Two pucks collide on a frictionless air table. The initial motion is along the x-axis and video analysis gives the final velocity vectors.

A particle with momentum 5.0 kg m s⁻¹ along the positive x-axis decays into two particles. Particle 1 has momentum 3.0 kg m s⁻¹ at 30° above the x-axis.

Two pucks collide on a frictionless table. The initial total momentum components of the system are $(1.8,0)\, ext{kg m s}^{-1}$. After the collision, puck A has momentum components $(0.70,0.50)\, ext{kg m s}^{-1}$.

In a two-dimensional collision experiment, students measure the total momentum components before and after a collision as follows:

Before: $(0.96,0.00)\, ext{kg m s}^{-1}$

After: $(0.91,0.08)\, ext{kg m s}^{-1}$

Each component has an uncertainty of $\pm0.06\, ext{kg m s}^{-1}$.

A stationary puck is struck by an identical moving puck. The final directions of the pucks are measured for several trials.

An initially stationary object explodes into three fragments on a horizontal surface. The momentum vectors of two fragments are measured.

A simulation models ideal gas molecules colliding with a wall. The table gives the number of collisions per second and the average perpendicular momentum change per collision for different temperatures.

A box is held at rest on a rough inclined plane by a rope parallel to the plane.

A particle beam experiment records two-dimensional momentum components before and after a collision.

A safety engineer compares a rigid barrier with a deformable crash barrier for stopping the same moving cart.

A laboratory collision experiment uses two low-friction carts on a track. One cart is initially moving and the other is initially at rest. Students measure masses and velocities before and after the collision.

A rider in an amusement-park rotor moves in a horizontal circle against the inside wall of a vertical cylinder. The floor is lowered and the rider does not slide down.

A moving puck collides obliquely with a stationary puck on a horizontal air table. The final velocity directions and speeds of both pucks are measured.

The pressure of an ideal gas can be interpreted in terms of molecular collisions with the container walls.

An initially stationary object explodes into three fragments on a horizontal surface. A camera records the speed and direction of each fragment.

Two experiments investigate conservation of momentum. Experiment 1 is a one-dimensional collision between carts. Experiment 2 is a two-dimensional collision between pucks on an air table.