# Work done on the block by force

by Zmuffinz
Tags: block, force, work
 P: 6 1. The problem statement, all variables and given/known data A block is pushed across a rough horizontal surface from point A to point B by a force (magnitude P = 5.4 N) as shown in the figure. The magnitude of the force of friction acting on the block between A and B is 1.2 N and points A and B are 0.5 m apart. If the kinetic energies of the block at A and B are 4.0 J and 5.6 J, respectively, how much work is done on the block by the force P between A and B? 2. Relevant equations W= PCos (theta)D 3. The attempt at a solution I have no idea what to do for this!
 P: 766 I suppose Work done on the block = change in kinetic energy + work against friction
HW Helper
Thanks
PF Gold
P: 26,105
Hi Zmuffinz! Welcome to PF!

(have a theta: θ )
 Quote by Zmuffinz W= PCos (theta)D … I have no idea what to do for this!
Well, what is θ in this case?

P: 6

## Work done on the block by force

well you see thats why im stuck, i wasnt given an angle, or mass of the block or anything so ive got no clue as to what to do:(
P: 6
 Quote by songoku I suppose Work done on the block = change in kinetic energy + work against friction
and how do i calculate work against friction?
Mentor
P: 40,689
 Quote by Zmuffinz well you see thats why im stuck, i wasnt given an angle, or mass of the block or anything so ive got no clue as to what to do:(
You didn't post the diagram, but I presume that the force was applied horizontally. That will tell you all you need about angles.

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