A student of mass $62\ \text{kg}$ stands on a scale in a lift. The lift accelerates upwards at $1.8\ \text{m s}^{-2}$.

A block of mass $4.0\ \text{kg}$ is pulled at constant speed along a horizontal surface by a horizontal force of $11\ \text{N}$.

A tennis ball of mass $0.058\ \text{kg}$ approaches a racket horizontally at $18\ \text{m s}^{-1}$ and leaves in the opposite direction at $24\ \text{m s}^{-1}$. The contact time is $5.0\ \text{ms}$.

A car travels at constant speed around a flat circular bend of radius $48\ \text{m}$. The coefficient of static friction between the tyres and the road is $0.62$.

In a kinetic model of an ideal gas, molecules move in random directions and collide with the walls of a container.

A small ring is held at rest by three light strings. One string is attached to a force sensor, one is horizontal, and one supports a hanging mass. The annotated diagram shows the forces acting on the ring and the angle of the force-sensor string to the horizontal.

A student loads and unloads a spring. The graph shows the applied force against extension for both loading and unloading.

A small steel sphere of radius $1.2\ \text{mm}$ falls vertically through oil at constant terminal speed. The density of steel is $7.8\times10^3\ \text{kg m}^{-3}$, the density of the oil is $9.0\times10^2\ \text{kg m}^{-3}$ and the viscosity of the oil is $0.65\ \text{Pa s}$.

Two dynamics carts move on a horizontal track. Cart A has mass $0.35\ \text{kg}$ and speed $1.6\ \text{m s}^{-1}$ to the right. Cart B has mass $0.55\ \text{kg}$ and is initially at rest. After the collision the carts stick together.

A puck of mass $0.20\ \text{kg}$ moves on a horizontal air table at $3.0\ \text{m s}^{-1}$ along the positive $x$-direction. It collides with a stationary puck of mass $0.30\ \text{kg}$. After the collision, the $0.20\ \text{kg}$ puck moves at $1.5\ \text{m s}^{-1}$ at $40^\circ$ above the positive $x$-axis.

An object initially at rest explodes into three fragments on a frictionless horizontal surface. Fragment A has momentum $0.80\ \text{kg m s}^{-1}$ east. Fragment B has momentum $0.60\ \text{kg m s}^{-1}$ north.

A ball of mass $0.16\ \text{kg}$ moving horizontally strikes a smooth vertical wall and rebounds. Just before impact its velocity is $7.0\ \text{m s}^{-1}$ at $30^\circ$ to the normal to the wall. Just after impact its velocity is $6.0\ \text{m s}^{-1}$ at $30^\circ$ to the normal, on the other side of the normal. The contact time is $0.012\ \text{s}$.

A nucleus initially at rest emits an alpha particle and a recoiling daughter nucleus. The alpha particle has momentum $3.6\times10^{-20}\ \text{kg m s}^{-1}$ at $25^\circ$ above the positive $x$-axis. A gamma photon carries momentum $1.1\times10^{-20}\ \text{kg m s}^{-1}$ along the negative $y$-axis.

A block is pulled across a horizontal surface by a steadily increasing horizontal force. The graph shows the frictional force on the block against the applied force. The normal force on the block is $40\ \text{N}$.

A puck of mass $0.160\ \text{kg}$ moves towards a wall with speed $6.0\ \text{m s}^{-1}$. The positive direction is away from the wall. The graph shows the resultant force on the puck during contact with the wall.

Two identical pucks collide on a low-friction table. One puck is initially at rest. The vector diagram and table show the measured speeds and directions after the collision.

A molecule of mass $4.65\times10^{-26}\ \text{kg}$ collides with a vertical wall of a container. The diagram shows the velocity components immediately before and immediately after the collision.

Two identical smooth discs collide on a horizontal air table. Disc A initially moves at speed $2.4\ \text{m s}^{-1}$ along the positive $x$-direction and disc B is initially at rest. After the collision, disc A moves at $1.4\ \text{m s}^{-1}$ at $35^\circ$ above the original direction and disc B moves at $1.9\ \text{m s}^{-1}$ at $50^\circ$ below the original direction.

A small smooth sphere falls through oil. Its speed is measured using light gates after release. The graph shows speed against time. The radius of the sphere is $1.20\times10^{-3}\ \text{m}$, its weight is $1.20\times10^{-4}\ \text{N}$, and the buoyancy force on it is $3.0\times10^{-5}\ \text{N}$.

A rubber stopper of mass $0.080\ \text{kg}$ is whirled in a horizontal circle. The radius is varied while the centripetal force is kept constant. The graph shows $T^2$ against radius $r$, where $T$ is the period.

Two pucks collide on a horizontal air table. Puck A is initially moving along the positive $x$-direction and puck B is initially at rest. The table gives the masses and the measured velocities immediately after the collision.

A small object initially at rest explodes on a smooth horizontal surface into three fragments A, B and C. The table gives the masses and velocities of fragments A and B immediately after the explosion. Fragment C has mass $0.200\ \text{kg}$.

A neutron collides elastically with a stationary proton in a cloud chamber. The masses of the neutron and proton may be taken as equal. The diagram shows the measured directions and speeds after the collision.

A crate of mass $12\ \text{kg}$ is at rest on a rough plane inclined at $28^\circ$ to the horizontal. A light rope pulls the crate up the plane with a tension of $35\ \text{N}$.

A tennis ball of mass $0.058\ \text{kg}$ approaches a racket with speed $12\ \text{m s}^{-1}$ in the negative direction. The force exerted by the racket on the ball varies during contact as shown.

A dynamics cart A of mass $0.60\ \text{kg}$ moves at $2.4\ \text{m s}^{-1}$ along a horizontal track and collides with a stationary cart B of mass $0.90\ \text{kg}$. The carts stick together after the collision.

A video of two carts colliding on an air table is analysed frame by frame. Successive frames are separated by $0.040\ \text{s}$. The grid and table show the positions used to calculate velocities just before and just after the collision. The masses are $0.200\ \text{kg}$ for cart A and $0.300\ \text{kg}$ for cart B.

A small steel sphere falls vertically through oil. The radius of the sphere is $1.5\times10^{-3}\ \text{m}$ and the density of steel is $7.8\times10^3\ \text{kg m}^{-3}$. The density of the oil is $9.0\times10^2\ \text{kg m}^{-3}$ and its viscosity is $0.85\ \text{Pa s}$.

A ball of mass $0.25\ \text{kg}$ is attached to a light string of length $0.80\ \text{m}$ and moves in a vertical circle. The speed of the ball is $3.4\ \text{m s}^{-1}$ at the top of the circle and $6.0\ \text{m s}^{-1}$ at the bottom.

A model rocket is launched vertically upward. Its initial mass is $0.75\ \text{kg}$. During the first $2.0\ \text{s}$, fuel is ejected at a constant rate of $0.080\ \text{kg s}^{-1}$ with speed $620\ \text{m s}^{-1}$ relative to the rocket.

A puck P of mass $0.20\ \text{kg}$ moves at $5.0\ \text{m s}^{-1}$ along a frictionless air table and collides with a stationary puck Q of mass $0.30\ \text{kg}$. After the collision, P moves at $3.0\ \text{m s}^{-1}$ at $40^\circ$ above its original direction.

An object initially at rest explodes on a smooth horizontal surface into three fragments. Fragment A has mass $0.40\ \text{kg}$ and moves east at $6.0\ \text{m s}^{-1}$. Fragment B has mass $0.30\ \text{kg}$ and moves north at $5.0\ \text{m s}^{-1}$. Fragment C has mass $0.50\ \text{kg}$.

On a horizontal air table, glider A of mass $0.50\ \text{kg}$ moves east at $1.6\ \text{m s}^{-1}$ and glider B of mass $0.40\ \text{kg}$ moves north at $1.2\ \text{m s}^{-1}$. They collide and stick together.

Two identical pucks collide on a horizontal air table. Puck A initially moves east at $1.8\ \text{m s}^{-1}$ and puck B is initially at rest. After the collision, A moves at $1.1\ \text{m s}^{-1}$ at $35^\circ$ north of east.

A neutron in a moderator is modelled as colliding with a stationary hydrogen nucleus of approximately the same mass. Before the collision, the neutron travels at $2.0\times10^6\ \text{m s}^{-1}$ in the positive $x$-direction. After the collision, the neutron travels at $1.2\times10^6\ \text{m s}^{-1}$ at $50^\circ$ above the positive $x$-direction.