work and power

Question 1

What is the formula for work done?

Answer 1

Work done (W) = Force (F) × Distance moved (d)

Question 2

What is work done measured in?

Answer 2

Joules (J)

Question 3

How is work done related to energy transfer?

Answer 3

Work done is equal to the energy transferred.

Question 4

What is the formula for gravitational potential energy?

Answer 4

GPE = mass (m) × gravitational field strength (g) × height (h)

Question 5

If you lift an object higher, what happens to its GPE?

Answer 5

It increases because height (h) increases.

Question 6

What is the value of gravitational field strength (g) on Earth?

Answer 6

9.8 N/kg

Question 7

What is the formula for kinetic energy?

Answer 7

KE = ½ × mass (m) × speed² (v²)

Question 8

If the speed of an object doubles, how does its KE change?

Answer 8

It increases by four times (since KE depends on speed squared).

Question 9

How does the conservation of energy link GPE, KE, and work?

Answer 9

Energy is transferred between GPE, KE, and work done, but total energy is conserved.

Question 10

What is power?

Answer 10

Power is the rate of energy transfer or the rate of doing work.

Question 11

What is the formula for power?

Answer 11

Power (P) = Work done (W) ÷ Time (t)

Question 12

What is power measured in?

Answer 12

Watts (W), where 1 W = 1 joule per second.

Question 13

If a machine transfers 100 J of energy in 2 seconds, what is its power?

Answer 13

P = 100 ÷ 2 = 50 W