Question

Find the distance travelled
(26) A body starts its motion with zero velocity and its acceleration is 3m
by it in fifth second
(A) 15.5m
(B) 17.5m
(C) 13.5m
(D) 145m​

Answer 1

Correct question :

A body starts its motion with zero velocity and its acceleration is 3m/s² Find the distance travelled by it in fifth second.

Answer:

The distance travelled in 5th second

(C) 13.5m

Step by step explanations :

given that,

A body starts its motion with zero velocity and its acceleration is 3m/s²

here,.

initial velocity of the body will be 0 m/s

and.

acceleration will 3 m/s²

to find,

distance travelled in 5th second,

let the distance travelled in 5th second we S5

so,

by the equation of motion,

Sn = u + a/2(2n - 1)

where,

u = initial velocity,

a = acceleration

n = number of second

now,

putting the values,

S5 = 0 + 3/2{(2(5) - 1}

= 3/2(10 - 1)

= 3/2(9)

= 27/2

= 13.5 m

so,

The distance travelled in 5th second

= 13.5 meter

Answer 2

Mistake in question

Correct question :

A body starts its motion with zero velocity and its acceleration is 3 m / s² Find the distance travelled by it in 5th seconds.  

by it in fifth second

Answer:

$\displaystyle{S_5=13.5 \ m}$

C. option is correct.

Explanation:

Given :

Initial velocity ( u ) = 0 m / sec

Acceleration ( a ) = 3 $m/sec^2$

n th second ( n ) = 5

We have

$\displaystyle{S_n=u+\frac{1}{2} \ a \ (2n-1) }$

where

u = initial velocity

a = acceleration

n = n th time

Put the value here we get

$\displaystyle{S_5=0+\frac{1}{2} \ 3 \ (2\times5-1)}\\\\\displaystyle{S_5=\frac{1}{2} \ 3 \ (9)}\\\\\displaystyle{S_5=3 \times4.5}\\\\\displaystyle{S_5=13.5 \ m}$

Thus , distance travelled by body is 13.5 m.