If a car is traveling 100 km/h west and comes to a stop in 3 min, what is the car's acceleration?

0.15 m/s2 east

0.15 m/s2 west

0.56 m/s2 east

0.56 m/s2 west

0.15 m/s² east

Explanation:

We can use following kinematic equation for Uniformly-Accelerated Motion to solve this problem:

Where v is the final velocity, v₀ is the initial velocity, a is the acceleration and t is the time interval.

The data of the problem is:

Replacing the data in the formula:

0 km/h = -100 km/h + a × 3 min

It's very important to use the same units when solving problems. I will convert kilometer to meters and hour or minutes to seconds, because the answer choices are given in m/s².

Then:

And considering our frame of reference, a positive sign indicates that the acceleration is east-bound.

one centimetre is equal to 0.01 metres

option c is the correct answer.