5004 Shares

Physics word problem help please?

Physics word problem help please? Topic: Problem solving four steps to
May 19, 2019 / By Jordon
Question: When a driver brakes an automobile, friction between the brake disks and the brake pads converts part of the car's translational kinetic energy to internal energy. If a 1360 kg automobile traveling at 36.4 m/s comes to a halt after its brakes are applied, how much can the temperature rise in each of the four 3.5 kg steel brake disks? Assume the disks are made of iron (cp = 448 J/kg·°C) and that all of the kinetic energy is distributed in equal parts to the internal energy of the brakes. ____ °C rise in temperature
Best Answer

Best Answers: Physics word problem help please?

Georgene Georgene | 7 days ago
Amount of energy to be dissipated by the brakes: K.E. = 1/2 * m * v^2 = 1/2 * 1360 * 36.4^2 = 900973 Joules Amount of energy for each brake: 900973 / 4 = 225243 Joules (rounding off to nearest '1') 225243J / (3.5 kg * 448 J / kg*degreeC ) = 144 degree C rise. This last step is solved by simply taking the information in the problem and figuring out how to cancel out dimensions (J/J and kg/kg) until you are left with degreesC, only. .
👍 102 | 👎 7
Did you like the answer? Physics word problem help please? Share with your friends

We found more questions related to the topic: Problem solving four steps to


Georgene Originally Answered: Physics Relative Velocity Problem, please help I've been doing physics for 5 hours now and my brain is fried!
Here's help getting started. Going upstream will slow you down by the amount of the current's speed; going downstream will speed you up by the amount of the current's speed. Your upstream speed (relative to the bank) is 8m/s–1m/s = 7m/s. Your downstream speed (relative to the bank) is 8m/s+1m/s = 9m/s SO: How long does it take to go 175m at a speed of 7m/sec? How long does it take to go 175m at a speed of 9m/sec? Add those two times.
Georgene Originally Answered: Physics Relative Velocity Problem, please help I've been doing physics for 5 hours now and my brain is fried!
looks like a tricky question, but you're over thinking it. the boat is going 8 m/s relative to the water, so that means if you're on the water the boat seems to pass at 8 m/s. when it goes with the current, it's really going 9 m/s, and against the current 7 m/s. since you're going the same distance against and with the current, it will average out to 8 m/s. so take the total distance (350m) and divide by 8 to get 43.75 seconds. This of course disregards acceleration/deceleration and the time it takes the boat to turn around, but that would be more advanced than the problem seems to call for
Georgene Originally Answered: Physics Relative Velocity Problem, please help I've been doing physics for 5 hours now and my brain is fried!
The key to this problem is the motion of the water. Essentially, the water is moving at a constant speed, like a treadmill. No matter how much you are moving or not, you will be moved by the water at 1m/s. The boat is your runner, he has a maximum speed he can run at, whether it's against or with the treadmill, at 8m/s. However, we're interested in his displacement relative to the enviroment. So, when you're moving downstream, you're moving at 8m/s 'running' speed + 1m/s for the water, for a sum speed of 9m/s. When you're moving upstream, the current is working against you, so you lose 1m/s to the water and have a sum speed of 7m/s. The overall travel time is thus the time it takes to cover 175m at 9m/s plus the time it takes to cover the same 175m at 7m/s.

Della Della
Hummmm organic or semi metalic brake pads? too many veriances to give a correct answer. I wouldn't worry about it! Hahahahhaa follow the 2 second rule and ya should be fine.
👍 30 | 👎 6

Della Originally Answered: MS WORD question: I am trying to burn a disk of word files and it keeps saying there is a problem with some of
There could be more than one cause to your problem. 1 - Make sure you are using the right type of disk for the format of your burner (1a - make sure you are using a writable CD or DVD burner). There are many types of disk types, here are the basic types: DVD-R/-RW/+R/+RW/CD-R/CD-RW. 2 - Make sure there is room on the disk you are trying to burn. Some formats allow disks to be used over and over again. If the disk you are writing to has already been used, it's possible you just don't have enough space. 3 - Make sure the files you are trying to access are not being used by another program. Close all other applications before trying to burn the files. 4 - Make sure the hard drive you are reading from has not been corrupted. Run scandisk to make sure the hard drive is in good shape. It wouldn't hurt to defragement the hard drive as well. If none of these help, try a simple test to burn other types of files other than MS-Word to a disk. If you succeed, then you know that it is isolated to just the MSWord files (I doubt that is the case). If you have trouble with other types of files, it may be the software you are using (assuming it is not any of the issues I have listed above). Good luck!

If you have your own answer to the question problem solving four steps to, then you can write your own version, using the form below for an extended answer.