Physics Review 1

How long will it take a 1792-W motor to lift a 3592-N table to a window 1.3 m above?

Answer explanation

2.61 s

What is the work done by a spring that is attached on the wall while a person is pulling a block?

• Zero

• Positive

• Negative

• Cannot be determined

What is the work done by your hand when you throw a stone?

• Zero

• Positive

• Negative

• Cannot be determined

What is the work done when you push the wall in your room?

• Zero

• Positive

• Negative

• Cannot be determined

What is the work done by friction between the car's tires and the road?

• Zero

• Positive

• Negative

• Cannot be determined

At which point is the kinetic energy the highest?

• Point A

• Point B

• Point C

• Point D

A 0.5-kg billiard ball that is moving at 9.8 m/s strikes the bumper of a pool table and bounces straight back at 2.9 m/s. The collision lasts 0.05 s. Calculate the average force exerted on the ball by the bumper.

Answer explanation

-127

A man carries a 1.5-kg luggage while walking 7.1 meters. What is the work done by the man's hand on the luggage?

Answer explanation

0

A 0.9-kg object moves in a horizontal circular track with a radius of 4.3 m. An external force of 5 N, always tangent to the track, causes the object to speed up as it goes around. The work done by the external force as the object makes one revolution is equal to _______.

Answer explanation

135.02

Zoe pushes a piano on a smooth level floor at a distance of 10 m from the starting position and has a work done equal to 301 J. How much force did Zoe exert to push the piano?

Answer explanation

30.1