Work and Power

What is work?

• When a force causes an object to move in the direction of the force

• When a force is applied to an object but it doesn't move

• When a force is applied to an object in the opposite direction of its motion

• When a force is applied to an object at rest

Which of the following is an example of work?

• Pushing a car that doesn't move

• Lifting a heavy box and holding it still

• Climbing up a flight of stairs

• Throwing a ball in the air

How can work be calculated?

• By multiplying force applied to the object by the distance it moves

• By dividing force applied to the object by the distance it moves

• By adding force applied to the object and the distance it moves

• By subtracting force applied to the object from the distance it moves

What is power?

• The amount of work done by a force

• The rate at which energy is transferred

• The distance an object moves

• The force applied to an object

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

How is power calculated?

• By dividing the amount of work done by the time it takes

• By multiplying the amount of work done by the time it takes

• By adding the amount of work done and the time it takes

• By subtracting the amount of work done from the time it takes

What is the unit used to express power?

• Joules

• Newtons

• Meters

• Watts

How can power be increased?

• By increasing the amount of work done

• By decreasing the amount of work done

• By increasing the amount of time it takes

• By decreasing the amount of time it takes

When riding a bike, if you put out 50 joules of work in 5 seconds, what is your power?

• 5 joules per second

• 10 joules per second

• 15 joules per second

• 20 joules per second

What must happen for work to be done on an object?

• The object must move as the force is applied and the direction of the object's motion is the same as the direction of the force

• The object must move as the force is applied and the direction of the object's motion is opposite to the direction of the force

• The object must not move as the force is applied

• The object must move before the force is applied

Tags

NGSS.MS-PS2-2

Which car is more powerful?

• The race car

• The friendly family car

• Both cars have the same power

• Power cannot be determined based on the given information