Work and Power

State the SI unit for Work

• Joule (Jo)

• Newton (N)

• Watt (w)

• Joule (J)

( (a)   ) is defined as the force exerted on an object multiplied by the distance the object moves in the direction of the force

A crate of mass 50kg is pushed along a floor with a force of 20N for a distance of 5m. Calculate the work done.

• 2500 J

• 250 J

• 100 J

• 1000 J

A car is pushed with a force of 300 N. The car moves 50 m horizontally. What is the work done?

• 15000 J

• 1500 J

• 15000 N

• 1500 N

Calculate the time taken for a crane that uses 750 W to lift a load 2000 N to a height 0f 6 m

• 16 second

• 18 second

• 16,5 second

• 18,5 second

How far must a 5 N force pull a 50 gram toy car if 30 Joule of energy are transferred?

• 6 m

• 16,6 m

• 10 m

• 0,6 m

Marie lifts a 10 kg mass from the floor and puts in on a table 2 metre high. What is the work done?

• 20 J

• 20 N

• 200 N

• 200 J

( (a)   ) is the rate of doing work or the amount of energy transferred per unit time.

Formula of Work done!

Formula of Power!