contestada

A tennis pro throws a tennis ball at a speed of 204 km/hr. a) The tennis racquet contacts the 0.057 kg ball for 0.25 s, therefore what is the average force on the ball?
b) The ball doesn't get slowed down by drag or friction, and the opponent returns the ball at a speed of 80 km/hr. Assuming a contact time of 0.25 s, what average force is applied to the ball by the opponent’s racquet?

Respuesta :

Answer:12.92 N, 17.98 N

Explanation:

Given

Speed of ball[tex]=204 km/hr \approx 56.667m/s[/tex]

mass of ball (m)=0.057 kg

time (t)=0.25 s

(a)Average Force(F)[tex]=\frac{mv}{t}[/tex]

[tex]=\frac{0.057\times 56.667}{0.25}[/tex]

[tex]=\frac{3.2300}{0.25}[/tex]

=12.92 N

(b)Intial velocity(u) [tex]=204 km/hr \approx 56.667[/tex]

Final velocity (v)[tex]=80 km/hr \approx 22.22 m/s[/tex]

Average Force[tex]=\frac{0.057\left ( 56.667+22.22\right )}{0.25}[/tex]

F=17.984 N

Otras preguntas