A skateboarder, with an initial speed of 3.8m/s , rolls virtually friction free down a straight incline of length 20m in 3.3 s.
At what angle ? is the incline oriented above the horizontal?
answer to two significant figures
mgsin[theta] = ma
S = ut + a*t*t/2
20 = 3.8*3.3 + a *3.3*3.3/2
a = 2.527m/sec2
9.8sin[thetha] = 2.527
angle = 14.9396degree