Question

a dog runs with an initial speed of 7.5 m/s on a waxed floor. it slides to a stop in 15 seconds. what is the acceleration? 7.5 mi//hr, -7.5 m/s², -0.5 m/s², -7.5 m/s

Explanation:

Step1: Recall acceleration formula

The formula for acceleration \( a \) is \( a=\frac{v - u}{t} \), where \( v \) is final velocity, \( u \) is initial velocity, and \( t \) is time.

Step2: Identify values

Initial velocity \( u = 7.5\space m/s \), final velocity \( v = 0\space m/s \) (since it stops), time \( t = 15\space s \).

Step3: Substitute into formula

\( a=\frac{0 - 7.5}{15} \)

Step4: Calculate

\( a=\frac{- 7.5}{15}=- 0.5\space m/s^{2} \)

Answer:

-0.5 m/s² (corresponding to the orange option: -0.5 m/s²)