In the Soapbox Derby in (Figure 1), young participants build non-motorized cars
ID: 1650695 • 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 55-ft-long (1 m = 3.28 ft) section tilled 14 below horizontal. What a 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
a)
The component of gravity along an incline is g sin(theta), so for this incline the maximum possible acceleration is 9.81 sin 14 = 2.4 m/s^2
(This of course assumes no friction between the wheels and surface, but this is the maximum possible value )
b)
To find speed, use
vf^2=v0^2+2ad
vf=final velocity
v0=initial velocity =0
a=accel = 2.4m/s^2
d=distance =55 feet = 55/3.28 m = 16.77m
vf^2=0^2+2*2.4*16.77
vf = 8.9 m/s