Question

What is the acceleration in the scenario below.

An object slows from 20 m/s to 12 m/s in 4 seconds. What is the
acceleration?
-2 m/s^2
2 m/s^2
5 m/s^2
-5 m/s^2

Answer 1

Acceleration is a measure of the change in velocity over time.
Change in velocity is Δv=v−u

Δv=-20+12=-8m/sec

Since this change in velocity takes place over 4 seconds,

Object’s acceleration is a=
Δt/Δv
​=-2m/saw

Answer 2

`\huge\boxed{\sf a = -2 \ m/s^2}`

Step-by-step explanation:

Given data:

Initial velocity =
`V_i` = 20 m/s

Final velocity =
`V_f` = 12 m/s

Time = t = 4 s

Required:

Acceleration = a = ?

Formula:

`\displaystyle a = (V_f-V_i)/(t)`

Solution:

Put the given data in the above formula.

`\displaystyle a =(12 - 20)/(4) \\\\a =(-8)/(4) \\\\a = -2 \ m/s^2\\\\\rule[225]{225}{2}`