Question

When a driver presses the brake pedal, his car can stop with an acceleration of -5.4m/s^2. How far will the car travel while coming to a complete stop if its initial speed was 25 m/s?

Answer 1

Information that is given:
a = -5.4m/s^2
v0 = 25 m/s
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S = ?
Calculate the S(distance car traveled) with the formula for velocity of decelerated motion:
v^2 = v0^2 - 2aS
The velocity at the end of the motion equals zero (0) because the car stops, so v=0.
0 = v0^2 - 2aS
v0^2 = 2aS
S = v0^2/2a
S = (25 m/s)^2/(2×5.4 m/s^2)
S = (25 m/s)^2/(10.8 m/s^2)
S = (625 m^2/s^2)/(10.8 m/s^2)
S = 57.87 m