A 65.0-kg basketball player jumps vertically and leaves the...

Name: Problem 14, Chapter 6: College Physics
Uploaded: 2019-10-25T21:50:35-08:00
Duration: 3 min 15 s
Channel: Averell Hause
Description: A 65.0-kg basketball player jumps vertically and leaves the floor with a velocity of 1.80 m/s upward. (a) What impulse does the player experience? (b) What force does the floor exert on the player before the jump? (c) What is the total average force exerted by the floor on the player if the player is in contact with the floor for 0.450 s during the jump?

A 65.0-kg basketball player jumps vertically and leaves the floor with a velocity of 1.80 m/s upward. (a) What impulse does the player experience? (b) What force does the floor exert on the player before the jump? (c) What is the total average force exerted by the floor on the player if the player is in contact with the floor for 0.450 s during the jump?

A 65.0-kg basketball player jumps vertically and leaves the floor with a velocity of 1.80 m/s upward. (a) What impulse does the player experience? (b) What force does the floor exert on the player before the jump? (c) What is the total average force exerted by the floor on the player if the player is in
contact with the floor for 0.450 s during the jump?

Key Concepts

Average Force

Average force refers to the constant force which, when acting over a specified time interval, produces the same impulse as that produced by a varying force over the same time period. It is determined by dividing the total impulse by the duration of time during which the force is applied.

Newton's Second Law of Motion

Newton's Second Law provides the relationship between force, mass, and acceleration, stating that the net force acting on an object is equal to the product of its mass and acceleration. This law is crucial for understanding how forces cause changes in an object's motion and is applied in calculations involving impulse and force.

Contact Time

Contact time is the duration during which an object is in contact with another object or surface while a force is being applied. It is an important factor in impulse calculations because a longer contact time with a given impulse would correspond to a smaller average force, and vice versa.

Impulse

Impulse is the change in momentum of an object resulting from the application of a force over a period of time. It quantifies the effect that forces have in altering the motion of objects, and is calculated as the product of the force applied and the time duration during which it is applied.

Impulse-Momentum Theorem

The impulse-momentum theorem is a fundamental principle in mechanics which states that the impulse on an object (the product of force and time) is equal to the change in its momentum. This theorem connects the application of forces over time to the resulting variation in an object's velocity and mass.

Transcript

00:01 So we're going to choose the positive direction to be upwards.

00:08 And we can then say that the impulse for part a would be equalling the change in the momentum.

00:14 This would be equaling the mass multiplied by the difference between the final velocity and the initial velocity.

00:19 So this would be equaling 65 .0 kilograms.

00:24 This would be multiplied by 1 .80 meters per second, the final velocity upwards, minus.

00:32 And it's zero meters per second.

00:34 And so we can say that the impulse would be 117 kilograms meters per second.

00:41 Again, this is positive.

00:43 So this is going to be in the direction of the final velocity.

00:47 Final velocity, again, being upwards.

00:50 So we can say that for part b, right before the jump, the player is an equilibrium.

00:56 So we can say that the sum of forces in the wide direction is going to equal the mass times the acceleration, the wide direction, this would be equaling 0.

01:05 And so we can say that the force of 1 is equaling mg, or we can say 65 .0 kilograms multiplied by 9 .8 meters per second squared.

01:18 This is equaling 637 newtons.

01:23 Again, this is positive.

01:24 We chose upwards to be positive.

01:26 This means that this is upwards...

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