Question

A man carries a 10 kg sack of groceries in his arms with a force of 50 N as he walks forward a distance of 10 m. How much work has he done?

0 J, 50 J, 100 J, or 500 J

***I am not 100% sure... I think it is either 0 J or 500 J ? Thank you!!

Answer 1

im thinking that the direction of force and the direction of displacement will play into solution.

Answer 2

okay!! how would we apply that here?

Answer 3

if we assume he is pushing the bag forward, then work is done moving forwards.

the bag stays stationary with regard to up and down ... so no work down in that direction.

Answer 4

ohh so then it would be 0? because 0*10? :/

Answer 5

since there's no working in that direction?

Answer 6

Work is force over a distance, W = Fxd

Answer 7

okay! so force of 50... direction of 0? 50 * 0 = 0 ? :/

Answer 8

You need to understand the problem before you apply the formula, notice work results when there's force upon the object which then causes displacement.

Answer 9

if you push a block horizontally using 50N to 10m the work done is 500Nm

so this question assumes that you know if there is any force being applied in the forward direction ...

Answer 10

ohhhh okay!! so i have to first identify what is what in the problem, and then apply? and 1 Nm is the same as 1 J is that correct?

Answer 11

Nm might be J ..... never retained that part of it lol

Answer 12

hahaha okie :P

thank you both!! @amistre64 @Astrophysics :)

Answer 13

So what you should question is if the FORCE and DISTANCE are in the same direction. So then you can apply your formula.

Answer 14

Also, amistre is correct, in saying the work done is 500 J or Nm :P

Answer 15

ohh okay!! :)

Answer 16

oh yay!! so Nm is equal to J :) woo!! thanks y'all!! :D

Answer 17

We use Nm mostly for torque but yes it's the same as Joules.