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!!!
Let
his and skateboard's combined mass is x
we know
F1=-F2
0.5kg*10m/s=-0.05m/s xkg
5=0.05x(minus cancel with the m/s as it represented the opposite direction of velocity and now there is no velocity in this equation.. so minus is avoidable. and the kgs cancel out)
x=10
so their combined mass is a 100 kg.. (I hope I didn't mess thing up for you)
I am sorry I cant find the answer. I was hoping to find the answer
Answer:
option A
Explanation:
given,
height of the drop of stone = 9.44 m
speed of the stone = ?
As the stone is dropped the energy of the stone will be conserved.
using conservation of energy.
Potential energy = Kinetic energy
v = 13.60 m/s
Hence, the correct answer is option A
