Revision 3 - variety of questions

Question 1

A petrol fuelled car (not electric or hybrid) speeds down the road when the driver hits the brakes. If the car begins with kinetic energy, what will it end with?

Answer 1

Thermal energy

Question 2

A strong man lifts weights. If the weight gain is gravitational potential energy, what did the strongman get energy in the form of?

Answer 2

Chemical energy

Question 3

John uses a Cherry Picker to lift him 15m in order to tile his roof. If John’s mass is 70kg, how much GPE does he gain? (gravity 9.8 N/Kg)

Answer 3

10,290J because 70 * 9.8 * 15

Question 4

Tina does 25J of work to move her bag 50cm, how much force did she use?

Answer 4

50N because 50/100 = 0.5 and 25/0.5

Question 5

A motor transfers 10000J of energy in 25s. Work out it’s power.

Answer 5

400W because P = 10000/25

Question 6

Calculate how long it takes Bert to lift a cheeseburger to his mouth, doing 0.5J of work while using 2W of power.

Answer 6

0.25s because 0.5/2

Question 7

What is the mass in kg, of Bindi, who does 1400J of work climbing a 2m high ladder?

Answer 7

70KG because 1400/2 = 7000/10