Work, Energy, and Power

What is the unit for work?

• N.m²

• (Kg.m²) / s²

• J/m

• J

In which scenario is work = 0 J ?

• Pushing a stationary wall

• Pulling a trolley car

• Pushing a book across the table

• Dropping a set of keys from a height, h.

An object weighing 20 N moves horizontally toward the right a distance of 5.0 m. What is the work done on the object by the force of gravity?

• The work done on the object by the force of gravity is 50 J.

• The work done on the object by the force of gravity is zero joules.

• The work done on the object by the force of gravity is 0.25 J.

• The work done on the object by the force of gravity is 100 J.

Which of the following indicates negative work being done?

• The road exerts a frictional force on a speeding car skidding to a stop.
• A rope exerts a force on a bucket as the bucket is raised up a well.
• A person pushes a car to the nearest gas station after running out of gas.
• Gravity pulls a baseball downward after it is dropped.

Which of followings states work equation? 

• Work = Force x Distance
• Work = Force x Acceleration 
• Work = Distance x Momentum
• Work = Newton x Acceleration 

Tags

NGSS.MS-PS3-5

You pushed a box with force of 50N to West. If the boxed moved 2 m to West, what is your work? 

• 100 N
• 0 N
• 100 J
• 50 m/s

A person pushes horizontally on a large box with a force of 165 N for a distance of 2.8 m. The force of friction acting on the box is 148 N. What is the total work done on the box? (Round your answer to a whole number)

• 51 J

• 49 J

• 47 J

• 45 J

What is energy due to motion? 

• Kinetic Energy
• Mechanical Energy
• Chemical Potential Energy
• Elastic Potential Energy

Which of followings correctly shows Kinetic Energy equation?

• KE = 1/2 x mass x velocity²

• KE = 1/2 x motion x acceleration

• KE = 1/2 x momentum x force x speed

• KE = 1/2 x mass x speed

Kolby is 100 kg. He was running to his house with speed of 10 m/s. What is Kolby's kinetic energy? 

• 1,000 J
• 5,000 J
• 50,000 J
• 500,000 J