Refer a friend and earn $50 when they subscribe to an annual planRefer Now

Get the answer to your homework problem.

Try Numerade Free for 30 Days

Like

Report

One 110-kg football lineman is running to the right at 2.75 m/s while another 125-kg lineman is running directly toward him at 2.60 m/s. What are (a) the magnitude and direction of the net momentum of these two athletes, and (b) their total kinetic energy?

(a) $P_{x}=m_{A} v_{A x}+m_{B} v_{B x}=(110 \mathrm{kg})(2.75 \mathrm{m} / \mathrm{s})+(125 \mathrm{kg})(-2.60 \mathrm{m} / \mathrm{s})=-22.5 \mathrm{kg} \cdot \mathrm{m} / \mathrm{s} .$ The netmomentum has magnitude $22.5 \mathrm{kg} \cdot \mathrm{m} / \mathrm{s}$ and is directed to the left.(b) $K=\frac{1}{2} m_{A} v_{A}^{2}+\frac{1}{2} m_{B} v_{B}^{2}=\frac{1}{2}(110 \mathrm{kg})(2.75 \mathrm{m} / \mathrm{s})^{2}+\frac{1}{2}(125 \mathrm{kg})(2.60 \mathrm{m} / \mathrm{s})^{2}=838 \mathrm{J}$

Physics 101 Mechanics

Chapter 8

Momentum, Impulse, and Collisions

Section 1

Momentum and Impulse

Moment, Impulse, and Collisions

University of Washington

Simon Fraser University

University of Sheffield

Lectures

04:16

In mathematics, a proof is…

04:48

In mathematics, algebra is…

02:40

One $110-\mathrm{kg}$ foot…

08:22

An 88 kg fullback moving e…

02:03

A $90.0-\mathrm{kg}$ fullb…

04:04

Two skaters collide and gr…

05:44

On a very muddy football f…

06:02

06:40

09:25

A 90.0-kg fullback running…

04:21

$\bullet$ On a very muddy …

05:24

A football player with a m…

problem. 8.5 way have thes two football lineman running towards each other, the masses and speeds shown. And we want to know. First of all, what is the net momentum of the system formed by these two alignment running at each other? And then what is the net kinetic energy? Uh, from you know, they're having some mass and speed, so we'll call this the positive X direction are just the positive direction, since this is one dimensional. Doesn't call this, but let's call it six. So the momentum is going to be the momentum of this lineman who, since he's running in the direction of called Positive, this would be positive and it's going to be his mass times. The speed when I didn't 10 kilograms times two point. So I mean, it's per second. And then this lineman is running in the negative extraction. So let's attract his momentum from from that of the first day over here, and that this is going to be 100 and 25 kilograms times two points, six meters per second. And then if you, uh, do all of your asthma tick here, this will work out to be negative, 22.5. That's Graham meters per second. So this is the direction negative X direction with and then this is a magnitude. Now we'd like to do is find out what the net kinetic energy of all this is. And similarly, we just add up the kinetic energy of each part of the system. That'll tell us how much we're dealing with. So recalled it. It's 1/2 and B squared. So 1/2 I'm sorry, 110 kilograms times five squared plus an hour Adding this because the spirit here is always going to be positive. So even if we were accounting for the fact we called were saying, This guy's running in the negative direction, this still ends up Being positive because we've squared is also technically a speed is is positive because it's the magnitude of the velocity. You know, we're using the bubble butt. This is 125 kilograms, and he's going slightly slower 2.6 meters per second, which we will spare and then going through the numbers here, you'll find this is 838 Jules. So this is the direction and magnitude of their mo mentum. So I'm going to the left is this guy's a little bit bigger and this is their total kinetic energy.

View More Answers From This Book

Find Another Textbook

Numerade Educator

In mathematics, a proof is a sequence of statements given to explain how a c…

In mathematics, algebra is one of the broad parts of mathematics, together w…

One $110-\mathrm{kg}$ football lineman is running to the right at 2.75 $\mat…

An 88 kg fullback moving east with a speed of $5.0 \mathrm{m} / \mathrm{s}$ …

A $90.0-\mathrm{kg}$ fullback running east with a speed of 5.00 $\mathrm{m} …

Two skaters collide and grab on to each other on frictionless ice. One of th…

On a very muddy football field, a 110 -kg linebacker tackles an $85-$ kg hal…

On a very muddy football field, a 110-kg linebacker tackles an 85-kg halfbac…

A 90.0-kg fullback running east with a speed of 5.00 m/s is tackled by a 95.…

$\bullet$ On a very muddy football field, a $110-$ kg linebacker tack-le…

A football player with a mass of 88 $\mathrm{kg}$ and a speed of 2.0 $\mathr…

04:30

To warm up for a match, a tennis player hits the 57.0-g ball vertically with…

07:21

Charge $Q$ is distributed uniformly throughout the volume of an insulating s…

06:12

It was shown in Example 21.10 (Section 21.5) that the electric field due to …

02:07

Fields from a Light Bulb. We can reasonably model a 75-W incandescent light …

02:49

The fastest pitched baseball was measured at 46 m/s. A typical baseball has …

02:05

You pull horizontally on block $B$ in $\textbf{Fig. E4.26}$, causing both bl…

01:32

A projectile thrown from a point $P$ moves in such a way that its distance f…

11:10

A physics professor is pushed up a ramp inclined upward at 30.0$^\circ$ abov…

01:21

Based on the given data, how does the energy used in biking 1 km compare wit…

05:05

You plan to take your hair dryer to Europe, where the electrical outlets put…

92% of Numerade students report better grades.

Try Numerade Free for 30 Days. You can cancel at any time.

Annual

0.00/mo 0.00/mo

Billed annually at 0.00/yr after free trial

Monthly

0.00/mo

Billed monthly at 0.00/mo after free trial

Earn better grades with our study tools:

Textbooks

Video lessons matched directly to the problems in your textbooks.

Ask a Question

Can't find a question? Ask our 30,000+ educators for help.

Courses

Watch full-length courses, covering key principles and concepts.

AI Tutor

Receive weekly guidance from the world’s first A.I. Tutor, Ace.

30 day free trial, then pay 0.00/month

30 day free trial, then pay 0.00/year

You can cancel anytime

OR PAY WITH

Your subscription has started!

The number 2 is also the smallest & first prime number (since every other even number is divisible by two).

If you write pi (to the first two decimal places of 3.14) backwards, in big, block letters it actually reads "PIE".

Receive weekly guidance from the world's first A.I. Tutor, Ace.

Mount Everest weighs an estimated 357 trillion pounds

Snapshot a problem with the Numerade app, and we'll give you the video solution.

A cheetah can run up to 76 miles per hour, and can go from 0 to 60 miles per hour in less than three seconds.

Back in a jiffy? You'd better be fast! A "jiffy" is an actual length of time, equal to about 1/100th of a second.