Question

1. Michelle's mass is 25 kg. Stacy's mass is 36 kg. They have the same scooters which have the mass of 1.36 kg.They both rode the scooters on a stretch of flat road measuring 15.24 meters. They did so in 6 seconds. What was the momentum of each girl?

2. Explain whether or not it is possible for Michelle to achieve the same momentum as Stacy. In your explanation, be sure to include the math that supports your choice.

Hint: The scooter's max speed is 4.47 m/s.

can someone show me how to work this?

Answer 1

First of all , the problem tells us the distance traveled by the girls and the time it took them to travel that distance (15.24 meters and 6 seconds)

With this, we calculate the speed V = 15.24/6 m/s= 2.54 m/s

The momentum is defined as mass times velocity, .........P = m*V

For each girl

Michelle...............

P1 = (M1 +Scooter mass)*V = (25+1.36)*2.54 kg*m/s = 65.95 kg*m/s

Stacy..............

P2 = (M2 +Scooter mass)*V = (36+1.36)*2.54 kg*m/s = 94.89 kg*m/s

Stacy's momentum is higher than Michelle's but lets remember the Hint, The scooter's max speed is 4.47m/s.

If Michelle were to increase the speed of her scooter, she would achieve a higher momentum.

Lets calculate the speed it would take for Michelle to achieve the same momentum as Stacy.

(25kg + 1.36kg)*V = 94.89 kg*m/s..........==>

V = 94.89/26.36 m/s = 3.6 m/s !

Which is less than the scooter's maximun speed, so it is possible to achieve Stacy's momentum