Question

Q6: A car moving at 50m/s decreases its speed to 30m/s in 4 seconds. What is its acceleration?​

Answer 1

Answer:

Acceleration= -5m/s²

Explanation:

Acceleration = change of velocity/time

                      = 30-50/ 4s

                      = -20/4

Acceleration= -5m/s²

When it take as reatardation or deacceleration is 5m/s²

Answer 2

Answer:

Correct option is

B

8 s

Given Final velocity (v) = 50 m/s

Initial velocity (u) = 30 m/s

Acceleration (a) = 2.5 m/s

2

We know v = u + at

∴ 50 = 30 + 2.5 t

⇒ 50 - 30 = 2.5 t

⇒

2.5

20

= t or 8 = t

∴ Time taken to accelerate = 8 seconds