Question

A student pushes a 40-N block across the floor for a distance of 10 m. How much work was applied to move the block?

A.
4 J

B.
40 J

C.
400 J

D.
4000 J

Answer 1

The correct answer to the question is C) 400 J.

CALCULATION:

As per the question, the force applied on the block F = 40 N.

The distance travelled by the block S = 10 m.

We are asked to calculate the work done by the block.

The work done by a body under a force F is calculated as -

Work done W =
`\vec F.\vec S`

=
`FScos\theta`

Here,
`\theta` is the angle between force and displacement.

If
`\theta =\ 0^(0)`, then work done W =
`FScos0`

= FS. [ cos0 = 1]

Hence, the work done by the block W = FS

= 40 N × 10 m

= 400 Joule. [ans]

Here, Joule is the unit of work.

Hence, the work done by the block s 400 Joule.