Which of the choices is the best description of work?

• a quantity that describes when an object is moved over a distance by a force applied to the object in the direction that it is moving

• the net force acting on an object

• the amount of work done in a given amount of time

• the stored energy of an object due to its position

Which of the statements regarding the concept of work in physics are true?

• Work is a scalar quantity.

• Work is measured by sweat.

• Work depends on the angle between the applied force on an object and the object's displacement.

• Pushing against an immovable object is an example of work being done.

• Work can be positive, negative, or zero.

Tags

NGSS.HS-PS3-2

Work is done…

• On a toy car as you push it around the floor

• On the locked door that remains closed while you try to pull it open

• On books as you lift them and place them on the bookcase

• On the door as your push against it and open it.

• On the bowling ball that you are holding while waiting for your turn to bowl.

A sled is pulled horizontally across the snow for a distance of 53 m by a force of 124 N. How much work is done on the sled?

• 2.9 J

• 6600 J

• .35 J

• 6572 J

A worker pushes a box across the floor with a force of 101N for a distance of 23.0 m. How much work was done on the box by the worker?

• 2320 J

• 7.87 J

• .127 J

• 2323 J

An ant pushes a piece of a leaf across the ground using a force of 0.000344 N for a distance of 5.7 m.

How much work was done by the ant on the leaf?

• 0.0020 J

• 0.00196 J

• 4900 J

• 4942 J

Tags

NGSS.MS-PS3-5

Which of the choices is a correct description of the work-energy theorem?

• The work on an object can be determined by subtracting the initial kinetic energy from the final kinetic energy.

• The work on an object can be determined by finding how many times larger the final kinetic energy is than the initial kinetic energy.

• The work on an object can be determined by finding the sum of both the initial and final kinetic energy.

• The work on an object can be determined by subtracting the final kinetic energy from the initial kinetic energy.

The work-energy theorem defines the relationship of the net work on an object and the change in the kinetic energy of the object.

Based on the the work-energy theorem, if the net work on an object is more than 0 J, the kinetic energy of the system will...

• Increase

• Decrease

• Remain Constant

Tags

NGSS.HS-PS3-1

Use the work-energy theorem to determine the amount of work it would take to change the kinetic energy of an object from 2814 J to 7456 J.

• -4642 J

• 4642 J

• 10270 J

• -10270 J

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

How much work would it require to take a speed boat from an initial kinetic energy of 5725 J to a final kinetic energy of 1391 J?

• 4334 J

• -4334 J

• 7116 J

• -7116 J

Tags

NGSS.HS-PS3-1