chapter 8

Question 1

calculating work done

Answer 1

force x distance is direction of force
W = F x D
work done = joules (J) but also can be given as Nm
1J = 1N x 1M = 1Nm

Question 2

work done triangle

Answer 2

work (top)

force and distance moved (left/right)

Question 3

calculating power

Answer 3

power = energy transferred / time taken
or
power = work done / time taken

power (watts (W)
watts is the power when 1 j of work is done in 1 second
1W = 1j/s

Question 4

power triangle

Answer 4

work (top)

power and time (left/right)

Question 5

power, work done and time taken

Answer 5

faster the work, greater the power

ways to increase power : left heavier object at same time and lift object quicker

Question 6

power meaning

Answer 6

rate at which work is done
or
the rate at which energy is transferred

Question 7

forces doing no work

Answer 7

no movement in direction of force, the force does not worrk

Question 8

work done

Answer 8

energy is capacity of something to do work

• work is done whenever a force acts on an object that moves or is moving in the direction of the force
• greater force, greater work
• greater distance, larger the work
• when any work is done, energy gets transferred from one form to another, the amount of energy transferred is equal to work done
• if force acts same direction as object moving, it gain energy (and opposite way to)