How do momentum and force relate

We will consider systems with varying mass in some detail; however, the relationship between momentum and force remains useful when mass is constant, such as in the following example. What is the average force exerted on the 0. This problem involves only one dimension because the ball starts from having no horizontal velocity component before impact.

To determine the change in momentum, substitute the values for the initial and final velocities into the equation above. Skip to main content. Linear Momentum and Collisions. Search for:. Linear Momentum and Force Learning Objectives By the end of this section, you will be able to: Define linear momentum.

Explain the relationship between momentum and force. Calculate momentum given mass and velocity. Example 1. Calculating Momentum: A Football Player and a Football Calculate the momentum of a kg football player running at 8.

Strategy No information is given regarding direction, and so we can calculate only the magnitude of the momentum, p. Making Connections: Force and Momentum Force and momentum are intimately related. Science eStore. Question How is force related to momentum? Asked by: Melissa Thomas Answer Momentum measures the 'motion content' of an object, and is based on the product of an object's mass and velocity.

Momentum doubles, for example, when velocity doubles. Similarly, if two objects are moving with the same velocity, one with twice the mass of the other also has twice the momentum. Knowing the amount of force and the length of time that force is applied to an object will tell you the resulting change in its momentum.

Answered by: Paul Walorski, B. On the other hand, you can also say that the change in momentum is equal to the force multiplied by the time in which it was applied or the integral of force with respect to time, if the force is not constant over the time period.

A longer collision time means the force on the occupants of the car will be less. Deaths during car races decreased dramatically when the rigid frames of racing cars were replaced with parts that could crumple or collapse in the event of an accident.

You may have heard the advice to bend your knees when jumping. In this example, a friend dares you to jump off of a park bench onto the ground without bending your knees. You, of course, refuse. Explain to your friend why this would be a foolish thing. Show it using the impulse-momentum theorem. Talk about the different strategies to be used while solving problems. Make sure that students know the assumptions made in each equation regarding certain quantities being constant or some quantities being negligible.

No information is given about the direction of the football player or the football, so we can calculate only the magnitude of the momentum, p. A symbol in italics represents magnitude. In both parts of this example, the magnitude of momentum can be calculated directly from the definition of momentum:.

Although the ball has greater velocity, the player has a much greater mass. Therefore, the momentum of the player is about 86 times greater than the momentum of the football. What was the average force exerted on the 0. As noted above, when mass is constant, the change in momentum is given by.

To determine the change in momentum, substitute the values for mass and the initial and final velocities into the equation above. In this case, using momentum was a shortcut. Use the Check Your Understanding questions to assess whether students master the learning objectives of this section. If students are struggling with a specific objective, the assessment will help identify which objective is causing the problem and direct students to the relevant content.

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