Question

A 2.0-kg ball moving eastward at 3.0 m/s suddenly collides with and sticks to a 4.0-kg ball moving northward at 2.0 m/s. What is the magnitude of the momentum of this system just after the collision?

Answer 1

10 kg m/s

Step-by-step explanation:

According to the law of conservation of momentum, the total momentum before the collision must be equal to the total momentum after the collision. So, we can simply calculate the total momentum before the collision.

The two balls are moving in perpendicular directions - one eastward and one northward. If we take eastward as positive x-direction and northward as positive y-direction, this means that we can find the magnitude of the total momentum by simply using Pythagorean theorem.

The magnitude of the momentum of the ball travelling eastward is:

`p_1 = m_1 v_1 = (2.0 kg)(3.0 m/s)=6.0 kg m/s`

The magnitude of the momentum of the ball travelling northward is:

`p_2 = m_2 v_2 = (4.0 kg)(2.0 m/s)=8.0 kg m/s`

So the magnitude of the total momentum is:

`p=√(p_1^2 +p_2^2)=√((6.0)^2+(8.0)^2)=10kg m/s`