This is a question related to work.
Today we had a pop quiz in my physics class and I am just trying to check my work here :D
1)
if there is a 5 kg block on a horizontal table connected with string to a 3 kg block hanging off the side of the table through a pulley. Assume the string is weightless and friction is neglectable in the system.
if the 5kg block moved .5 meters without any external force/pushing. What is the work done to the system?
I got:
work done = Net force * displacement
= (3kg*9.8)*(0.5)
= 14.7 Joules//
2)
assume some condition and displacement in part 1, what is the net work on the system if there is a friction Coefficient of 0.25 between the table and the 5kg block?
It would just be the 14.7 - (0.25*normal F)(0.5) of 5kg block right?
so the ans will be
14.7- 6.125
= 8.575 Joules//