Question

A body is moving with initial velocity 40m/sec. After 5 sec the velocity becomes 10m/sec. Find out the value of retardation in this 5 sec journey. *
2 points
5m/sec^2 (5 meter per second square)
10m/sec^2 (10 meter per second square)
6m/sec^2 (6 meter per second square)
None of these​

Answer 1

Answer:

6m/sec^2

Explanation:

From the question ,

u=40m/s,v=10m/s,t=5sec

we know that,

v=u+at ,

10=40+a×5

10=40+5a

-30=5a

a=-30/5

a=-5m/sec^2

therefore, retardation is 6

Answer 2

Given :

Initial velocity = 40m/s

Final velocity = 10m/s

Time interval = 5s

To Find :

We have to find acceleration of body$.$

Concept :

Acceleration is defined as the rate of change of velocity.

It is a vector quantity having both magnitude as well as direction.

SI unit : m/s²

Formula : a = v - u / t

Calculation :

$\dashrightarrow\rm\:a=\dfrac{v-u}{t}$

$\dashrightarrow\rm\:a=\dfrac{10-40}{5}$

$\dashrightarrow\rm\:a=\dfrac{-30}{5}$

$\dashrightarrow\underline{\boxed{\bf{\purple{a=-6\:ms^{-2}}}}}\:\orange{\bigstar}$

[Note : Negative sign shows retardation.]