Work Energy and Power

A weightlifter lifts two 300 newton weights 1.5 meters off the ground. How much work has he done?

• 600 J 

• 660 J

• 900 J 

• 1200 J 

You do 90 joules of work in 30 seconds. How much power have you generated?

• 30 watts

• 3 watts

• 120 watts

• 270 watts

Tags

NGSS.MS-PS3-5

You move a 0.8 kg object five meters in 4 seconds. How much power have you generated?

• 160 watts

• 10 watts

• 6.4 watts

• 17 watts

Which of the following would produce the most power?

• A mass of 10 kilograms lifted 10 meters in 10 seconds 

• A mass of 10 kilograms lifted 10 meters in 5 seconds

• A mass of 5 kilograms lifted 10 meters in 5 seconds

• A mass of 5 kilograms lifted 5 meters in 10 seconds

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

How much work does an elephant do while moving a circus wagon 20 meters with a pulling force of 200N?

• 4000 joules

• 10 joules

• 220 joules

• 180 joules

Tags

NGSS.MS-PS3-5

A 10 kg mass is lifted to 3 m. What is its weight? What is its potential energy? How much work is being done?

• Weight = 30 N

  PE = 30 J

  Work = 294 J

• Weight = 10 kg

  PE = 10 J

  Work = 30 J

• Weight = 98 N

  PE = 294 J

  Work = 294 J

• Weight = 98 N

  PE = 294 J

  Work = 30 J

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-4

How much work is produced when 350 N is used to move a car 5 m (W=Fd)?

• 70 J

• 1750 J

• 355 J

• 175 J

Tags

NGSS.MS-PS3-5

A bulldozer does 30,000 J of work over a distance of 20 meters. How much force did it apply?

• 1500 N

• 2000 N

• 1000 N

• 2500 N

Answer explanation

To calculate force, use the formula: Force = Work / Distance. Therefore, Force = 30,000 J / 20 m = 1500 N. The correct answer is 1500 N.

Tags

NGSS.MS-PS2-2

What is the definition of power?

• Power is the product of force and velocity.

• Power is the product of force and work done per unit time.

• Power is the product of force per unit time and velocity.

• Power is the rate at which work is done.

Tags

NGSS.MS-PS3-5

A 5000N block is lifted 10 m. Calculate the work done.

• 50000 J

• 5000 J

• 500 J

• 50 J

Tags

NGSS.MS-PS3-2