Question

An aeroplane is moving with a horizontal velocity u at a height h above the ground. If a packet is dropped from it the speed of packet when it reaches the ground will be

• A. $\text{(}{\text{u}}^2+2gh{)}^{1/2}$
• B. $(2gh{)}^{1/2}$
• C. $(u^2-2gh{)}^{1/2}$
• D. $2gh$

Answer 1

The correct option is A $\text{(}{\text{u}}^2+2gh{)}^{1/2}$

Lets consider $u=$ initial velocity

$h=$height

$g=$ acceleration due to gravity

$v=$ speed at the ground

From 3rd equation of motion,

$v^2=u^2+2gh$

$v=\sqrt{u^2+2gh}$

$v=(u^2+2gh{)}^{1/2}$

The correct option is A.