physics
posted by unknown .
A sled with mass 20 kg is given a shove up a frictionless incline which makes an angle of 28 degrees with the horizontal. eventually the sled comes to rest at height of 1.35 m above where it started. a)calculate its initial speed. b)find the work done by the weight of the sled.

Vf^2 = = Vo^2 + 2gd = 0,
a. Vo^2  2*9.8 * 1.35 = 0,
Vo^2  26.46 = 0,
Vo^2 = 26.46,
Vo = 5.14m/s.
b. Fs = mg = 20kg * 9.8N/kg = 196N. =
Force of the sled.
196 @ 28deg.
Fp=196sin28 = 92N. = Force of the sled acting parallel to plane downward.
d=1.35m / sin28 = 2.88m = The distance traveled up the plane.
W = Fp*d = 92 * 2.88 = 265 Joules.