How is the joule related to the base units of $\mathrm{m}, \mathrm{kg} \& \mathrm{s}$?

A ${\mathrm{kgm}}^{-1}{ \mathrm{s}}^2$

B ${\mathrm{kgm}}^2{ \mathrm{s}}^{-2}$

C ${\mathrm{kg}}_{{\mathrm{In}}^2}{ \mathrm{s}}^{-1}$

D ${\mathrm{kgs}}^{-2}$

An object falls at terminal velocity in air. What overall conversion of energy is occurring?

A Gravitational potential energy to kinetic energy

B Gravitational potential energy to thermal energy

C Kinetic energy to gravitational potential energy

D Kinetic energy to thermal energy

Describe the energy changes taking place when an apple falling towards the ground.

Describe the energy changes taking place: when a car decelerating when the brakes are applied

Describe the energy changes taking place when a space probe falling towards the surface of a planet.

A $120 \mathrm{kg}$ crate is dragged along the horizontal ground by a $200 \mathrm{N}$ force acting at an angle of $30°$ to the horizontal, as shown.

The crate moves along the surface with a constant velocity of $0.5 \mathrm{m}{\mathrm{s}}^{-1}.$ The $200 \mathrm{N}$ force is applied for a time of $16 \mathrm{s}$.

Calculate the work done on the crate by the $200 \mathrm{N}$ force

A $120 \mathrm{kg}$ crate is dragged along the horizontal ground by a $200 \mathrm{N}$ force acting at an angle of $30°$ to the horizontal, as shown.

The crate moves along the surface with a constant velocity of $0.5 \mathrm{m}{\mathrm{s}}^{-1}.$ The $200 \mathrm{N}$ force is applied for a time of $16 \mathrm{s}$.

Calculate the work done on the crate by the weight of the crate

A $120 \mathrm{kg}$ crate is dragged along the horizontal ground by a $200 \mathrm{N}$ force acting at an angle of $30°$ to the horizontal, as shown.

The crate moves along the surface with a constant velocity of $0.5 \mathrm{m}{\mathrm{s}}^{-1}.$ The $200 \mathrm{N}$ force is applied for a time of $16 \mathrm{s}$.

Calculate the work done on the crate by the normal contact force $\mathrm{N}$.

A $120 \mathrm{kg}$ crate is dragged along the horizontal ground by a $200 \mathrm{N}$ force acting at an angle of $30°$ to the horizontal, as shown.

The crate moves along the surface with a constant velocity of $0.5 \mathrm{m}{\mathrm{s}}^{-1}.$ The $200 \mathrm{N}$ force is applied for a time of $16 \mathrm{s}$.

(b) Calculate the rate of work done against the frictional force $\mathrm{F}$.