Question

A football player kicks a ball at a 30o angle from the ground with an initial velocity of 15 m/s. What is the final velocity of the ball when it hits the ground?

Answer 1

Given that,

Angle = 30°

Initial velocity = 15 m/s

We need to calculate the time of flight

Using formula of time of flight

$T=\dfrac{2u\sin\theta}{g}$

Where, u = initial velocity

g = acceleration due to gravity

Put the value into the formula

$T=\dfrac{2\times15\sin30}{9.8}$

$T=1.5\ sec$

We need to calculate the final velocity of the ball

Using equation of motion

$v=u+gt$

$v=15+9.8\times1.5$

$v=29.7\ m/s$

Hence, The final velocity of the ball is 29.7 m/s.