hw19 - alexander (jra2623) homework 19 Turner (92510) 1...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: alexander (jra2623) homework 19 Turner (92510) 1 This print-out should have 13 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points What velocity must a car with a mass of 1290 kg have in order to have the same mo- mentum as a 2370 kg pickup truck traveling at 24 m / s to the east? Correct answer: 44 . 093 m / s. Explanation: Let : m 1 = 1290 kg , m 2 = 2370 kg , and v 2 = 24 m / s to the east . vectorp = m 1 vectorv 1 = m 2 vectorv 2 v 1 = m 2 v 2 m 1 = (2370 kg) (24 m / s) 1290 kg = 44 . 093 m / s to the east. 002 10.0 points Note: Take East as the positive direction. A(n) 80 kg fisherman jumps from a dock into a 137 kg rowboat at rest on the West side of the dock. If the velocity of the fisherman is 3 . 6 m / s to the West as he leaves the dock, what is the final velocity of the fisherman and the boat? Correct answer: 1 . 32719 m / s. Explanation: Let West be negative: Let : m 1 = 80 kg kg , m 2 = 137 kg kg , and v i, 1 = 3 . 6 m / s m / s . The boat and fisherman have the same final speed, and v i, 2 = 0 m/s, so m 1 vectorv i, 1 + m 2 vectorv i, 2 = ( m 1 + m 2 ) vectorv f m 1 vectorv i, 1 = ( m 1 + m 2 ) vectorv f v f = m 1 v i m 1 + m 2 = (80 kg) ( 3 . 6 m / s) 80 kg + 137 kg = 1 . 32719 m / s , which is 1 . 32719 m / s to the West. 003 10.0 points A(n) 871 N man stands in the middle of a frozen pond of radius 8 . 8 m. He is un- able to get to the other side because of a lack of friction between his shoes and the ice. To overcome this difficulty, he throws his 1 . 5 kg physics textbook horizontally toward the north shore, at a speed of 4 . 2 m / s. The acceleration of gravity is 9 . 81 m / s 2 . How long does it take him to reach the south shore? Correct answer: 124 . 02 s. Explanation: Let : W m = 871 N , r = 8 . 8 m , m b = 1 . 5 kg , and v b = 4 . 2 m / s . The mass of the man is m m = W m g . From conservation of momentum, m m v m + m b v b = m m v m + m b v b 0 = m m v m + m b v b v m = m b m m v b = g m b W m v b = ( 9 . 81 m / s 2 ) (1 . 5 kg) 871 N (4 . 2 m / s) = . 0709564 m / s . alexander (jra2623) homework 19 Turner (92510) 2 The time to travel the 8 . 8 m to shore is t = x | v m | = 8 . 8 m . 0709564 m / s = 124 . 02 s . 004 10.0 points An 67 . 1 kg object moving to the right at 47 . 2 cm / s overtakes and collides elastically with a second 51 . 1 kg object moving in the same direction at 28 . 1 cm / s. Find the velocity of the second object after the collision. Correct answer: 49 . 7854 cm / s. Explanation: Let : m 1 = 67 . 1 kg , m 2 = 51 . 1 kg , v 1 = 47 . 2 cm / s , and v 2 = 28 . 1 cm / s ....
View Full Document

Page1 / 7

hw19 - alexander (jra2623) homework 19 Turner (92510) 1...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online