Question

A car slows from 30 m/s to 15 m/s in 3 seconds. What is the acceleration of the car?

a) 5 m/s²
b) 10 m/s²
c) -5 m/s²
d) -10 m/s²

Answer 1

Speed decrease of 15m/s in 3 seconds

15/3=5

So the acceleration is c) -5m/s²

Answer 2

The acceleration of the car slowing from 30 m/s to 15 m/s in 3 seconds is -5 m/s², indicating a deceleration.

Step-by-step explanation:

The student's question involves determining the acceleration of a car as it slows down. The given information is that a car decelerates from 30 m/s to 15 m/s over 3 seconds. We can use the formula for acceleration, which is a change in velocity (Δv) divided by the time interval (Δt), a = Δv / Δt.

In this case, the change in velocity (Δv) is the final velocity (15 m/s) minus the initial velocity (30 m/s), which equals -15 m/s. We divide this by the time interval (Δt) of 3 seconds, resulting in an acceleration of -5 m/s². Therefore, the correct answer to the student's question is c) -5 m/s², indicating that the car is decelerating.