Energy - forces doing work and forces and their effects (8-9)

Question 1

What is work done?

Answer 1

When a force moves an object through a distance, work is done and energy is transferred.

E = F x d
E = work done/energy transferred (Nm or J)
F = force (N)
d = distance (m)

Question 2

What is power?

Answer 2

The rate at which energy is transferred.

P = E/t
P = power (W or J/s)
E = energy transferred (J)
t = time (s)

Question 3

What are some situations where forces can cause rotation?

Answer 3

A spanner turning a bolt, a seesaw and levers.

Question 4

What is the equation to find moments?

Answer 4

moment (Nm) = force (N) x distance normal to the direction of the force (m)

Question 5

What is the principle of moments?

Answer 5

Sum of clockwise moments = Sum of anticlockwise moments.