Work, energy and power

Which energy resource is not renewable?

• geothermal

• nuclear

• solar

• wind

The diagram shows part of a rollercoaster ride with the car at different positions. The car runs freely down from position X to position Y and up the hill on the other side.

What happens to the kinetic energy and to the gravitational potential energy of the car as it moves from position X to position Y?

• K.E = decreases, G.P.E = decreases

• K.E = decreases, G.P.E = increases

• K.E = increases, G.P.E = decreases

• K.E = increases, G.P.E = increases

Student P uses a force of 35 N to push a box 3.0 m across the floor. Student Q uses a force of 22 N to push another box 1.8 m across the floor. Which statement gives a full explanation why student P uses more energy than student Q?

• Student P pushes his box a greater distance than student Q.

• Student P pushes his box a greater distance and uses a bigger force than student Q

• Student P uses a bigger force than student Q.

• Student P pushes a heavier box than student Q.

The escalator takes 20 seconds to carry the man between the two floors. The useful work done against gravity is W. The useful power developed is P. The lift takes 30 seconds to carry the same man between the same two floors. How much useful work against gravity is done by the lift, and how much useful power is developed by the lift?

• work done by lift = more than W, useful power by lift = less than P

• work done by lift = more than W, useful power by lift = P

• work done by lift = W, useful power by lift = less than P

• work done by lift = W, useful power by lift = P

Which energy resource stores kinetic energy?

• nuclear

• wind

• coal

• solar

Two workers are stacking cans on to a shelf in a shop. The workers lift the same number of identical cans on to the same shelf from the same level. Worker P takes 3.0 minutes to lift the cans. Worker Q takes 4.0 minutes to lift the cans. Which statement about the workers is correct?

• Worker P develops less useful power than worker Q

• Worker P develops more useful power than worker Q

• Worker P does less useful work than worker Q.

• Worker P does more useful work than worker Q.

What needs to be known to calculate the work done by a force acting on an object?

• A

• B

• C

• D

A box of mass m and weight W is carried up some stairs of total height x and total width y. On which quantities does the work done against gravity on the box depend?

• m and y

• W and x

• W and y

• x and y

Which row gives the energy change in a battery and the energy change in a solar cell?

• battery = chemical to electrical, solar cell = electrical to light

• battery = chemical to electrical, solar cell = light to electrical

• battery = electrical to chemical, solar cell = electrical to light

• battery = electrical to chemical, solar cell = light to electrical

Which movement will require the greatest amount of work to be done?

• a force of 10N moving an object a distance of 3.0m

• a force of 10N moving an object a distance of 5.0m

• a force of 15N moving an object a distance of 3.0m

• a force of 15N moving an object a distance of 5.0m