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Ch. 09 - Linear Momentum
Giancoli Douglas - Physics for Scientists and Engineers 5th edition
Giancoli Douglas5th editionPhysics for Scientists and EngineersISBN: 9780137488179Not the one you use?Change textbook
Chapter 9, Problem 103a

In order to convert a tough split in bowling, it is necessary to strike the pin a glancing blow as shown in Fig. 9–64. Assume that the bowling ball, traveling at 14.0 m/s just before it strikes the pin, has five times the mass of a pin and that the pin goes off at 75° from the original direction of the ball. Calculate the speed of the pin and (b) of the ball just after collision.
Bowling ball colliding with a pin, showing angles and directions of motion after impact.

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1
Identify the type of collision: This is a two-dimensional elastic collision, as the bowling ball and pin move in different directions after the collision. Both momentum and kinetic energy are conserved.
Set up the conservation of momentum equations: Momentum is conserved in both the x-direction (original direction of the ball) and the y-direction (perpendicular to the original direction). Let the mass of the pin be m and the mass of the ball be 5m. Let the final velocity of the pin be v_p and the final velocity of the ball be v_b. The equations are: mv=mv

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Conservation of Momentum

The principle of conservation of momentum states that in a closed system, the total momentum before an event must equal the total momentum after the event, provided no external forces act on it. In this bowling scenario, the momentum of the bowling ball and the pin must be analyzed before and after the collision to determine their respective speeds.
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Elastic and Inelastic Collisions

Collisions can be classified as elastic or inelastic based on whether kinetic energy is conserved. In this case, the collision between the bowling ball and the pin is inelastic, meaning that while momentum is conserved, kinetic energy is not. This affects how we calculate the final velocities of the objects involved.
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Vector Components

When analyzing collisions, it is essential to break down velocities into their vector components, typically along the x (horizontal) and y (vertical) axes. This allows for the application of conservation laws in each direction separately, facilitating the calculation of the final speeds and directions of the bowling ball and pin after the collision.
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