posted by Aileen on .
I calculated parts a, b, c, but cannot figure out d. I tried combining all the forces and adding them but I am missing something?
There is an 18 kg box on a 32degree incline. a HORIZONTAL force of 150 N is given to the box
a) How much work is done by the horizontal force F = 150 N on the 18-kg block of the figure when the force pushes the block 5.1 m up along the 32degree incline? µk = 0.13.
ANSWER: 650 J
b) How much work is done by the gravitational force on the block during this displacement? -480 J
c) How much work is done by the normal force? 0J
d) What is the speed of the block (assume that it is zero initially) after this displacement?
I tried adding up (Fpcostheta - mgcostheta -Ffriction) but it doesn't work
Use the work-energy principle:
Initial velocity is zero therefore:
Ans: 4.3 m/s