Question

if a body has changed its velocity from 58m/s to 48m/s in 5s then how much is the acceleration of the body?​

Answer 1

Given :

Initial velocity : 58 m/s

Final velocity : 48 m/s

Time taken : 5s

To find :

The acceleration of the body

Solution :

Accerlation is the rate of change of velocity.

• It is a vector quantity having both magnitude as well as direction.
• SI unit of acceleration is metre per second square.

As we are provided with initial velocity, final velocity and time we can use first equation of motion that is,

v = u + at

here, v denotes initial velocity, u denotes final velocity, a denotes acceleration and t denotes time taken.

By substituting all the given values in the formula,

➝ v = u + at

➝ 48 = 58 + a(5)

➝ -10 = a(5)

➝ a = -10/5

➝ a = - 2m/s²

Thus, the acceleration of the object is -2 m/s².

If the speed is decreasing with time then accerlation is negative. The negative accerlation is called deceleration or retardation.

Answer 2

Given:-

• Initial velocity=u=58m/s
• Final velocity=v=48m/s
• Time=t=5s

To find:-

Acceleration

Solution:-

We know that

$\boxed{\sf Acceleration =\dfrac{v-u}{t}}$

$\\ \sf\longmapsto Acceleration=\dfrac{48-58}{5}$

$\\ \sf\longmapsto \dfrac{-10}{5}$

$\\ \sf\longmapsto -2m/s^2$