A bowling ball with a mass of 7.0kg strikes a pin that had a mass of 2.0kg the pin flies forward with a velocity of 6.0m/s, and the ball continues forward at 4.0 m/s. What was the original velocity of the ball?

The original velocity of the ball is 5.71 m/s.

The principle of conservation of momentum: In a closed system, The total momentum before collision is equal to total momentum after collision.

From the principle of conservation of momentum,

MU+mu = MV+mv Equation 1

Where M = mass of the bowling ball, m = mass of the pin, U = initial velocity of the bowling ball, u = initial velocity of the pin, V = final velocity of the bowling ball, v = final velocity of the pin.

From the question,

Given: M = 7 kg, m = 2 kg, u = 0 m/s (at rest), v = 6.0 m/s, V = 4 m/s.

Substitute these values into equation 1 and solve for U

7(U)+2(0) = 7(4)+2(6)

7U = 28+12

7U = 40

U = 40/7

U = 5.71 m/s.

Hence, The original velocity of the ball is 5.71 m/s.

Learn more about velocity here: link

The conservation of momentum P states that the amount of momentum remains constant when there are not external forces.

We don't have external forces, so:

Where:

Solving for v0b:

real, smaller and upside-down.   so the answer should be b.