Answer:
The speed of the car B after the collision is same as the speed of the car A before collision.
Explanation:
lets take the mass of the car A = m kg
Initial speed of the car A = u m/s
The mass of the car B = m kg
Initial speed of the car A = 0 m/s
The final speed of the car A = 0 m/s
The final speed of the car B = v
There is no any external force on the masses that is why the linear momentum will be conserve.
Initial linear momentum = Final linear momentum
P = mass x velocity
m u + m x 0 = m x 0 + m v
m u + 0 = 0 + m v
m u = m v
v= u
Therefore we can say that ,the speed of the car B after the collision is same as the speed of the car A before collision.
P = m . g
650 = m.10
m = 650/10
m = 65 kg
