Discrete Math: Applications of Dot Product
posted by Anonymous .
A 35kg trunk is dragged 10m up a ramp inclined at an angle of 12 degrees to the horizontal by a force of 90 N applied at an angle of 20 degrees to the ramp. At the top of the ramp, the trunk is dragged horizontally another 15m by the same force. Find the total work done.
Here's what I have so far:
35 x 9.8 = 343 N
And I don't know how to solve this problem. Please provide a step by step solution! I know you use the formula:
W = (F (dot) d)(cosx)
Textbook Answer: 2114 J

work=90*10*cos12 + 15*90*cos32
I am assuming the force does not change direction when one gets tothe top, the problem is unclear to me on that point. 
When calculated that equation to get an answer, it didn't match up with the textbook answer.