College Physics Problem 2.18

A commuter backs her car out of her garage with an acceleration of 1.40\:m/s^{2} .
(a) How long does it take her to reach a speed of 2.00 m/s?
(b) If she then brakes to a stop in 0.800 s, what is her deceleration?

SOLUTION:

a) The formula for acceleration is 

a=\frac{v_f-v_0}{t}

If we rearrange the formula by solving for the t, in terms of velocity and acceleration, we come up with

t=\frac{v_f-v_0}{a}

t=\frac{2.00\:m/s-0\:m/s}{1.40\:m/s^{2}}

t=1.43\:s

b) The formula for acceleration (deceleration) is 

a=\frac{v_f-v_0}{t}

a=\frac{0\:m/s-2\:m/s}{0.8\:m/s^{2}}

a=-2.50\:m/s^{2}

You can now buy the complete solution manual for College Physics. Just complete the google form below.

Advertisements