Linear Momentum-solutions

Linear Momentum-solutions - le (txl65) Linear Momentum...

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le (txl65) – Linear Momentum – mohanty – (81440) 1 This print-out should have 17 questions. Multiple-choice questions may continue on the next column or page – fnd all choices beFore answering. 001 10.0 points Two particles oF masses m and 3 m are moving toward each other along the x -axis with the same speed v . They undergo a head- on elastic collision and rebound along the x - axis. m v 3 m v Determine the fnal speed oF the heavier object. 1. v 3 m = 0 correct 2. v 3 m = v 3. v 3 m = 2 v 4. v 3 m = 2 3 v 5. v 3 m = 3 2 v 6. v 3 m = 1 2 v 7. v 3 m = 8. v 3 m = 3 v 9. v 3 m = 4 v 10. v 3 m = 1 3 v Explanation: Let : v 1 = v , v 2 = v , m 1 = m and m 2 = 3 m . Basic Concepts: Conservation oF momentum Solution: Denote the smaller mass initially moving to the right as m 1 and the larger mass initially moving to the leFt as m 2 . Since no external Forces act on the two masses, even during the collision, the total momentum is conserved. Also, since the masses collide elastically, en- ergy is conserved. Since this is a head on, elastic collision we can use v 2 = 2 v cm v 2 , where v cm = m 1 v 1 + m 2 v 2 m 1 + m 2 , so v 2 = 2 m 1 v 1 + 2 m 2 v 2 m 1 + m 2 v 2 ( m 1 + m 2 ) m 1 + m 2 = 2 m v 6 m v + m v + 3 m v m + 3 m = 0 . Alternative Solution: ±rom the relative velocities Formula, v 1 v 2 = v 2 v 1 . (1) ±rom conservation oF momentum, m 1 v 1 + m 2 v 2 = m 1 v 1 + m 2 v 2 . (2) Combining Eqs. 1 and 2 gives m 1 v 1 + m 2 v 2 = m 1 ( v 2 + v 2 v 1 ) + m 2 v 2 , v 2 = m 1 v 1 + m 2 v 2 m 1 ( v 2 v 1 ) m 1 + m 2 = m v + 3 m ( v ) m ( v v ) m + 3 m = m ( v 3 v + v + v ) 4 m = 0 . 002 10.0 points A 6 kg steel ball strikes a wall with a speed oF 9 . 26 m / s at an angle oF 35 . 6 with the normal to the wall. It bounces o² with the same speed and angle, as shown in the fgure.
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le (txl65) – Linear Momentum – mohanty – (81440) 2 x y 9 . 26 m / s 6 kg 6 kg 35 . 6 35 . 6 If the ball is in contact with the wall for 0 . 251 s, what is the magnitude of the average force exerted on the ball by the wall? Correct answer: 359 . 967 N. Explanation: Let : M = 6 kg , v = 9 . 26 m / s , and θ = 35 . 6 .
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This note was uploaded on 04/05/2011 for the course SD ds taught by Professor Sdsd during the Spring '11 term at Tarrant County.

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Linear Momentum-solutions - le (txl65) Linear Momentum...

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