Answer:
Correct answer: F₂ = 104.5 N
Explanation:
Given:
m = 57 g = 57 · 10⁻³ kg
Δt = 30 ms = 30 · 10 ⁻³ seconds
V₁ = 73.14 m/s service speed
V₂ = 55 m/s returned speed
M = m · V Momentum or Impulse
You forgot to indicate what time the ball contact when returning.
We will assume that the time is the same Δt = 30 ms = 30 10 ⁻³ seconds.
The formula for calculating force is according to Newton's second law is:
F = ΔM / Δt = m · ΔV / Δt
Force during service is:
F₁ = 57 · 10⁻³ · 73.14 / 30 · 10 ⁻³ = 138.97 N
F₁ = 138.97 N
Returned force:
F₂ = 57 · 10⁻³ · 55 / 30 · 10 ⁻³ = 104.5 N
F₂ = 104.5 N
God is with you!!!