A 46 kg box is being pushed a distance of 7.0 m across the floor by a force vector P whose magnitude is 148 N. The force vector P is parallel to the displacement of the box. The coefficient of kinetic friction is 0.25. Determine the work done on the box by each of the four forces that act on the box. Be sure to include the proper plus or minus sign for the work done by each force.(adsbygoogle = window.adsbygoogle || []).push({});

applied force - 1036 J (got this one right)

frictional force (J)-

normal force (J)-

gravity (J) -

1) I got the applied force right. For frictional force, Fk= 0.25 x Fn. I though the normal force equaled W, and W= 9.8 x 46 kg= 451 N. So for frictional force I got 113 N. Since it needs to be in J, I thought it had to be multiplied by the distance, 7 m, so I multiplied 113 by 7, but the answer is wrong.

2) For normal force, it also needs to be in J so I multiplied 451 by 7. The answer is wrong.

3) For gravity, not sure what to do.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Work Energy/Forces

**Physics Forums | Science Articles, Homework Help, Discussion**