A box of mass 16kg is pulled from rest a distance of 5m across a smooth horizontal floor by a cable inclined at to the horizontal. Find the work done by the tension in the cable given that its magnitude is 25N.

Question

A box of mass 16kg is pulled from rest a distance of 5m across a smooth horizontal floor by a cable inclined at  to the horizontal. Find the work done by the tension in the cable given that its magnitude is 25N.

jamesj · Answer

Work = (Force) x (Displacement in the direction of force)

Here, you have the force and the displacement.  Hence you just need to calculate.

jamesj · Answer

Make sense?  Talk to me.

anonymous · Answer

could you give me the answer?? make sense :D

jamesj · Answer

Well, the force is 25 N and what's the distance?

anonymous · Answer

5m

anonymous · Answer

but there is an angle given right?? why don't we include in the calc??

jamesj · Answer

Ah, what is that angle?

jamesj · Answer

Are you given a specific value?

anonymous · Answer

60 degree,and why they give us mass??

anonymous · Answer

cos 60 is 0.5

jamesj · Answer

As a distraction.  

Hence the force in the direction of motion, call it the x-direction, is

$$ F_x = F \cos(60) = 25 \frac{1}{2} $$

Hence work, W,
$$ W = F_x . d = \frac{25}{2} \cdot 5 \ \ \ N \cdot m $$

jamesj · Answer

Yes, sorry about that.

anonymous · Answer

thanks :D