In the Soapbox Derby in ( Figure 1 ) , young participants build non-motorized ca
ID: 1274737 • Letter: I
Question
In the Soapbox Derby in (Figure 1) , young participants build non-motorized cars with very low-friction wheels. Cars race by rolling down a hill. Assume that the track begins with a 49-ft-long (1 m = 3.28 ft) section tilted 14? below horizontal.
What is the maximum possible acceleration of a car moving down this stretch of track?
Express your answer to two significant figures and include the appropriate units.
If a car starts from rest and undergoes this acceleration for the full l, what is its final speed in m/s?
Express your answer using two significant figures.
Explanation / Answer
F = mgsin14 = ma
a = gsin14 = 2.37 m/s2
d = 49/3.28 = 14.94 m
v^2 -0 = 2 x 2.37 x 14.94
v = 8.41 m/s