Question

The initial velocity of a body moving along a straight line is 7 ms. It has a uniform acceleration of 4 ms. The distance covered by the body in the fifth second of its motion is
[ ]
a)25m
b) 12.5 m
d) 30 m
a) 20 m​

Answer 1

Answer:

Distance covered by the body in its fifth second is 25m

Explanation:

Given that,

The initial velocity of a body moving along a straight line, u = 7 m/s

The motion is uniformly accelerated.

Therefore the acceleration , a =  4 m$s^{-2}$

According to the equation of motion,

   Final velocity, v = u + at

    velocity after 4 seconds , v1 = u + at = 7 + (4 $\times$ 4) = 23 m/s

    velocity after 5 seconds , v2 = u + at = 7 + (4 $\times$ 5) = 27 m/s

Therefore distance covered by the body in its fifth second,

                     $S=\frac{v2^2-v1^2}{2a}=\frac{27^2-23^2}{2\times 4}=25m$