Answer:
F=65 N
Explanation:
Uniform Acceleration
When an object changes its velocity at the same rate, the acceleration is constant.
The relation between the initial and final speeds is:
[tex]v_f=v_o+a.t[/tex]
Solving for a:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
Where:
vf = Final speed
vo = Initial speed
a = Constant acceleration
t = Elapsed time
The ball is kicked from rest vo=0 to vf=32.5 m/s in t=0.21 s. Computing the acceleration:
[tex]\displaystyle a=\frac{32.5-0}{0.21}[/tex]
[tex]a=154.8\ m/s^2[/tex]
Note: We have shown this result rounded to the nearest tenth, but we kept all the decimals in a scientific calculator for further calculations.
The force needed to accelerate the soccer ball is calculated by:
F = ma
The ball has a mass of m=0.42 kg, thus:
F=0.42*154.8
F=65 N
As mentioned, this result can only be obtained by keeping full precision in the above calculations.
