Question

When talking a penalty kick, footballer applied a force of 30.0 N for a period of 0.05 s. If the mass of the ball is 0.075 kg, Calculate the speed with which the ball moves off.

Answer 1

$F = ma$

$a = \frac{F}{m}= \frac{30}{0.075}=400\frac{m}{s^2}$

$v_0= 0$

$a = \frac{v_1-v_0}{t}$

$v_1 = at= 400*0.05=20\frac{m}{s}$

$\text{Answer: }20\frac{m}{s}$