Answer:
a) The velocity of the ball upon leaving the foot = 600 m/s
b) Time to reach the goal posts 40.0 m away = 0.07 seconds
c) The kick won't e going inside goal post, it is higher by 10.34m.
Explanation:
a) Rate of change of momentum = Force
[tex]\frac{\texttt{Final momentum - Initial momentum}}{\texttt{Time}}=\texttt{Force}\\\\\frac{0.040v-0.040\times 0}{0.010}=2400\\\\v=600m/s[/tex]
The velocity of the ball upon leaving the foot = 600 m/s
b) Horizontal velocity = 600 cos20 = 563.82 m/s
Horizontal displacement = 40 m
Time
[tex]t=\frac{40}{563.82}=0.07s[/tex]
Time to reach the goal posts 40.0 m away = 0.07 seconds
c) Vertical velocity = 600 sin20 = 205.21 m/s
Time to reach the goal posts 40.0 m away = 0.07 seconds
Acceleration = -9.81m/s²
Substituting in s = ut + 0.5at²
s = 205.21 x 0.07 - 0.5 x 9.81 x 0.07²= 14.34 m
Height of ball = 14.34 m
Height of post = 4 m
Difference in height = 14.34 - 4 = 10.34 m
The kick won't e going inside goal post, it is higher by 10.34m.
