The velocity of B after elastic collision is 3.45m/s
This type of collision is an elastic collision and we can use a formula to solve this problem.
<h3>Elastic Collision</h3>

The data given are;
- m1 = 281kg
- u1 = 2.82m/s
- m2 = 209kg
- u2 = -1.72m/s
- v1 = ?
Let's substitute the values into the equation.

From the calculation above, the final velocity of the car B after elastic collision is 3.45m/s.
Learn more about elastic collision here;
brainly.com/question/7694106
The answer is B. A frame of reference that is accelerating.
Answer:
100m
Explanation:
100m
s=ut+1/2at^2
s= unknown, u=0, a=2, t=10
s=0*10+1/2(2)(10)^2
s=1/2(2)(100)
s=1(100)
displacement = 100 meters