L1 Mech 3 Work and Power

Front

What is the equation for work?

Back

W = F x d

Front

If you pull the trolley along a flat floor horizontally, which force do you use to calculate the work done?

Back

Pulling force

Front

If you pull the trolley vertically upwards using a crane, which force do you use to calculate the work done?

Back

Weight

Front

The force used in the work equation has to always be acting in the same direction as the movement of the object.

Back

True

Front

Which equation is the one for power?

Back

P = W / t

Front

Calculate the power of a snow lift that moves 50 m using 750 N of force in 75 seconds.

Back

500 W

Front

Ian and Steve ski down the 75 m slope in 80 seconds using 400 N of penguin force. Calculate their penguin power!

Back

375 W

Front

Mike and Peter are climbing to the top. Both take the same time, do the same route, but Mike has a mass of 25 kg while Peter has a mass of 30 kg. Which penguin does the most work and why?

Back

Peter as he does more work over the same time than Mike because he has a bigger weight force.

Front

Calculate the gravitational potential energy of a 500 kg roller coaster car at the top of a 20 m high ride.

Back

100 000J

Front

Calculate the work done getting a 500 kg roller coaster car to the top of a ride when pulled 30 m by a motor with a 4000 N force. The vertical distance from top to bottom is 20 m.

Back

120 000J