3NA Phy - Energy and work done

Define energy.

• Energy is equal to heat.

• Energy gives us strength.

• Energy is the ability to do work.

• Energy is something that we cannot see.

What is the unit for energy?

• E

• I

• H

• J

Marie applies a force of 50 N on the basket. She holds the basket 1 m above the floor.

Is there work done on the basket?

• Yes

• No

What is the formula for work done?

• W = FD

• F = WD

• D = WF

• W = D/F

A boy pushed a cart with a force of 200N for 30m. What is the work done?

(Formula is W = FD)

• 0.15 J

• 6.67 J

• 600J

• 6000J

_______________ and _____________ have energy in the chemical potential store .

• somewhere high and food

• food and battery

• battery and rubber band

• rubber band and a pulled bow

At which position does the girl's energy in the gravitational potential store the highest?

• None

• C

• A and E

• All

What is false when a man is lifting up a book?

• a force is applied on the book

• the book is moving

• the book moves in the direction of the force applied on it

• work is not done by the man as energy is not transferred from the man to the book

The total energy of an isolated system remains ................ because energy is conserved.

Energy is transferred from one object to another, or from one store to another.

• True

• False