Question

You are on a skateboard not moving when your friend throws you a basketball and you catch it. The 0.50kg basketball was going 5 m/s when you catch it. You weigh 55kg with the skateboard. After you catch the basketball you, the basketball, and the skateboard are moving.
a. What is your mass with the basketball and skateboard?
b. What is your new velocity after you catch the basketball?

Answer 1

Answer:

a. Your mass with the basketball is 55.5 kg

b. Your new velocity is 0.045 m/s

Explanation:

We first add your weight and the basketballs weight to get 55.5 kg.

Then to find b. we use the equation: v final = (m1 * v1) / (m1 +m2)

So m1 is the basketball which is 0.5 kg and v1 is 5 m/s. So the top half is (0.5 * 5)

The bottom half is just our weights added together.

Answer 2

Answer:

a) 55.5 kg

b) .045 m/s

Explanation:

Using conservation of momentum, we can set the initial momentum of the skateboard-person-basketball system equal to the final momentum of the skateboard-person-basketball system.

m1 = skateboard + person = 55 kg

m2 = basketball = .50 kg

v1_i = 0 m/s

v2_i = 5 m/s

Solve for v_f (same as v1_f or v2_f since the system is moving together -- assuming perfectly inelastic collision).

m1v1_i + m2v2_i = m1v1_f + m2v2_f

m1v1_i + m2v2_i = v_f (m1 + m2)

Substitute known values into the equation.

(55)(0) + (.5)(5) = v_f (55 + .5)

2.5 = v_f (55.5)

v_f = .045 m/s

Your new velocity after catching the basketball is .045 m/s.