Answer:
F = 4000 N
Explanation:
given,
mass of rocket (M)= 5000 Kg
10 Kg gas burns at speed (m)= 4000 m/s
time = 10 s
average force = ?
at the end the rocket is at rest
by conservation of momentum
M v + m v' = 0
5000 x v - 10 x 4000 = 0
5000 v = 40000
v = 8 m/s
speed of rocket = 8 m/s
now,
we know
change in momentum = F x Δ t
F = 4000 N
Hence, the average force applied to the rocket is equal to F = 4000 N
You should select Choice-4 .
I think the answer would be: The G-note's wavelength is longer
Here are the formula to calculate wavelength
Wavelength = Wave speed/Frequency
Which indicates that the wavelength will become larger as the frequency became smaller.