Question

A body is projected vertically upwards show that velocity of striking is equal to its velocity of projection numerically.​

Answer 1

Explanation:

mark me brain list hope it's help ful

Answer 2

Explanation,

Let us suppose the body is projected with a vertical speed of $Vm/s^{2}$

Considering the upward motion, we have

• Upward velocity = $Vm/s^{2}$

• Acceleration due to gravity acting in the opposite direction $a = -g$

Due to the negative acceleration, its velocity will become zero at some point during the time of its flight. We will calculate the height at which this happens.

Using formula, $2as = v^{2} - u^{2}$

$2*-g*s = 0 - V^{2}$   (final velocity is zero)

$s = \frac{V^{2} }{2g}$   ---------- eq(1)

Now, for the downward motion,

Initial velocity is 0,

Acceleration due to gravity is positive, acting in the direction of motion $a = g$

Using the same formula we can calculate its final velocity while striking,

using value of $s$ from eq(1).

$2g(\frac{V^{2} }{2g}) = v_{final} ^{2} - 0\\V^{2} = v_{final} ^{2} \\v_{final} = V$

Therefore, the velocity with which the body is projected is the same with which it strikes.

Hence, proved.