Question

A car goes from 30 m/s to 20 m/s in 2 seconds. What is the acceleration of the car in m/s2?

Answer 1

`\boxed{\sf Acceleration \ of \ the \ car = -5 \ m/s^2}`

Given:

Initial speed (u) = 30 m/s

Final speed (v) = 20 m/s

Time taken (t) = 2s

To Find:

Acceleration (a) of the car

Step-by-step explanation:

From equation of motion we have:

`\boxed{ \bold{v = u + at}}`

By substituting value of v, u & t in the equation we get:

`\sf \implies 20 = 30 + a(2) \\ \\ \sf \implies 2a + 30 = 20 \\ \\ \sf \implies 2a = 20 - 30 \\ \\ \sf \implies 2a = - 10 \\ \\ \sf \implies a = - (10)/(2) \\ \\ \sf \implies a = - 5 \: m {s}^( - 2)`

`\therefore`

Acceleration (a) of the car = -5 m/s²