problem involving vectors?

Question

plz. explain how to do it. I'm fine with just the formulas but would appreciate if everything was solved. :P


A ramp could be used to raise the concrete 20 m.
a) How much work would be required if the ramp formed at an angle 30 degrees with the horizontal?
b) How long would the ramp be?
c) How much force would be required?
(The component of the force // to the ramp.)
(Neglect friction)

Answer 1

you get a right angled triangle with on leg 20 m and the opposite angle 30º
so tan30 = 20 /x (x the other leg) so
x= 60/sqrt3 = 20*sqrt3
length of the ram = sqrt(400 +400*3)= 40m
Work done on the bl ock = =m*g*20 Nm ( m the mass in kg)
component of the force // to the ramp
m*g*20= F *40 so F= mg/2 Newton