Practice 6A: | 1 | 2 | 3 |Go up
Momentum  - by Matt Henderson, 2003

1. An Ostrich with a mass of 146 kg is running to the right with a velocity of 17 m/s . Find the momentum of the ostrich.

Here's what you know, m = 146 kg and v =17 m/s use the formula p = mv  to find the power

p = (146)(17) = 2482 kgm/s
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2. A 21 kg child is riding a 5.9 kg bike with a velocity of 4.5 m/s to the northwest.

a. What is the total momentum of the child and the bike together?

m( total) = 21 + 5.9 = 26.9 kg and v = 4.5 m/s 

use the formula p = mv         p = (26.9)(4.5) = 121.05 kgm /s 

b. What is the momentum of the child?

mass of child = 21 kg and the velocity is still v = 4.5 m/s

use p = mv         p = (21)(4.5) = 94.5 kgm/s

c. What is the momentum of the bike?

mass of the bike = 5.9 kg and v = 4.5 m/s still

use p = mv        p = (5.9)(4.5) = 26.55 kgm/s
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3. What velocity must a car with a mass of 1210 kg have in order to have the same momentum as the pickup truck in Sample Problem 6A? 

m = 1210 kg and the momentum of the pickup truck in Sample problem (In the book on the same page as these problems) 6A p = 5.6 X 10E4 kg m/s East 

use p = mv        5.6 X 10E4 = (1210)v             v = 46.28 m/s 
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