Question

The velocity of Desmond’s car changes from 20 meters/second to 10 meters/second. The change happens in 5 seconds. What’s the acceleration of the car? Use . 4 m/s2 2 m/s2 -2 m/s2 -4 m/s2

Answer 1

Answer: -2 m/s

Step-by-step explanation:

Answer 2

- 2 m/s²

Step-by-step explanation:

Acceleration is the rate of change of velocity with time.

Given,

Initial velocity = 20 m/s

Final velocity = 10 m/s

Time = 5s

Change of velocity = Final velocity - Initial velocity = 10 m/s - 20 m/s = - 10 m/s

Acceleration =
`(Change of velocity)/(Time)` =
`(-10 m/s)/(5s)` = - 2 m/s²

Here the minus sign (- 2 m/s²) indicates that the acceleration is actually decreasing. This is because the final velocity is lower than the initial velocity.