Physics - Work and Energy

Work is _________ when the component of force is in the SAME DIRECTION as the displacement. (p. 158)

When you lift a box, the work done by the force you exert on the box is positive because it is in the ________ ________ as the displacement. (p. 158)

Work is negative when the force is in the direction _________ the displacement. (p. 158)

The work done by the force of friction is __________ because it is in the opposite direction of the sliding object.

What is the answer to #1a on page 159?

• positive

• negative

• neutral

What is the answer to #1b on page 159?

• positive

• negative

• neutral

What is the answer to #1c on page 159?

• positive

• negative

• neutral

What is the answer to #2 on page 159?

• the neighbor does twice as much work

• you do twice as much work

• the neighbor does half as much work

• you do four times as much work

What is the answer to #3a on page 159?

Work = Force x distance

W = Fd

• 8280 J

• 345 J

• 36,000 J

• 2875 J

What is the answer to #3b on page 159?

Work = Force x distance

W = Fd

Force of friction (F_f) = coefficient of friction x normal force (F_n)

• 8880 J

• -7920 J

• -3600 J

• 790 J