Answer:
20,000 N
Explanation:
First find the acceleration:
a = Δv / Δt
a = (0 − 40 m/s) / 10 s
a = -4 m/s²
Next use Newton's second law to find the force on the car:
F = ma
F = (5000 kg) (-4 m/s²)
F = -20,000 N
According to Newton's third law, the force on the wall is equal and opposite the force on the car.
F = 20,000 N
Given:
Mass of the rail road car, m = 2 kg
velocity of the three cars coupled system, v' = 1.20 m/s
velocity of first car,
= 3 m/s
Solution:
a) Momentum of a body of mass 'm' and velocity 'v' is given by:
p = mv
Now for the coupled system according to law of conservation of momentum, total momentum of a system before and after collision remain conserved:
(1)
where,
= velocity of the first car
= velocity of the 2 coupled cars after collision
Now, from eqn (1)


v' = 1.80 m/s
Therefore, the velocity of the combined car system after collision is 1.80 m/s
Answer:
I think it's D) Guess why? I searched it up!