What is Brake: Definition and 138 Discussions

This isn't so much a homework question but rather something I need to know in order to design something. I need to know how much a brake rotor will heat up during braking. The force it needs to stop is a 120kg object traveling at 30 mph. I don't know any of the equations necessary to figure...

Is a prony brake a fairly accurate way to test HP. I built a prony brake just with wood to fit on a rotating shaft with a 1 foot arm. I get .75 of 1 HP if the shaft is rotating about 180 rpm and the arm lifts and holds 22 lbs. The diameter of the shaft is 2" - does that matter? And is a prony...

This is an interesting piece I am torn about. Copper from brake pads are known to run off into water ways. It is also known in lab experiments that the copper levels found in the water ways can affect salmon. Yet, there is no documentation for this happening in the wild. The state is going...

I've been trying to figure out the friction coefficient of some brake pads. My test fixture only allows me to pull (F2) a brake disc between two brake pads clamped around the disc with a force F1. I then measure with a load cell the maximum force required for the brake disc to slip. My...

Anyone can tell me what is kinetics energy that needs to be convert into heat energy by the brake?( I mean can show me the formula or any journal) Anyone know any relevant heat transfer formula needs to be applied in order to determine appropriate sizes and surface area for the brake in...

Homework Statement The tires of a 1500 kg car are 0.600 m in diameter and the coefficients of friction with the road surface are µs = 0.800 and µk = 0.600. Suppose the car has a disk brake system. Each wheel is slowed by the frictional force between a single brake pad and the disk-shaped...

i have to build a vehicle that can transport a battery 7 meters in a straight line as fast as possible using the potential enerygy of no more than two kilograms falling from a maximum height of 80.0 cm. i want to build this brake: http://www.scioly.org/w/images/1/19/SC-brake2diag.gif...

im struggling abit with this question. i have a formula but it doesn't really go with my question a brake disc has the following specification mean radius 0.16m force applied to each pad 5045N U = 0.35 brake disc rotational speed is 550rev/min work out its frictional torque work done...

Homework Statement A hydraulic brake system is shown. The area of the piston in the master cylinder is 6.35 cm2, and the area of the piston in the brake cylinder is 1.72 cm2. The coefficient of kinetic friction between the brake shoe and the wheel drum is 0.453. How large is the frictional...

I'm trying to understand just how the electric brake on my 24 Vdc lawnmower works. First, here is the circuit schematic: For the purposes of this discussion just note that, when the motor is shut off, the motor gets "shorted" when the main switch moves to the OFF/BRAKE position. Now, I...

Homework Statement A person is riding a bicycle at a constant speed v along a straight road and then gradually applies the brakes until the bicycle comes to a stop. Assume that the magnitude of the braking force increases liearly in time acordinto F = bt where b is a constant. The rider &...

Hello guys, my name is Danny and I am a mechanical engineer going through my undergrad and i have a question. Right now I am still doing my lower division courses and one of the things i need to do is to write a paper about ceramic brakes and the manufacturing process. So far I have borrowed a...

Can someone direct me to the best way to accomplish uni-direction braking of a rotating disc. I want very little friction in the free spin direction of rotation, and when the driving force is stopped, I need instant hold from reverse direction spin. Like a ratchet but quiter and smoother.

Hi, I want to create a electromagentic brake for AC motor. could you let me know how can I calculate wire lengh and what is the gauge of wire. if you have any calculating table please let me know. Regards, Naveen

I'm installing a set of front brake calipers on my track car, and the mounting brackets are made of aluminum (7075). What is the better mounting scenario - Thread the mounting bolts directly into the aluminum, or use a through hole mounting method with a proper bolt and nut combination? The...

Homework Statement Ok, I am designing a brake system for a uni project, as part of this i need to specify the size of the disc's, to prevent the brake fluid from boiling during braking. Does anyone know of an arbitary formula which will help me calculate the rate of heat loss from the...

Hello, I am working on a rough sketchup for a Mechanical Design Project involving a motorcycle brake. I am working on finding the Contact area of a brake pad on the rotor of a motorcycle. I have already found the torque and forces involved to actuate the pads against the rotor...

I have a simply question: how much force must be applied to an average car brake in order to fully depress the pedal? Also, if you know the answer, do you know where I could substantiate it? Thanks for any help you can offer.

Homework Statement Hi all, the question for revision is; A car of mass 600kg traveling at 45m/s comes to rest in 12m when the brakes are applied. What is the average force exerted by the brakes? Homework Equations Force = mass x acceleration V^2=u^2 +2as The Attempt at a Solution I know I...

In the brake shown in the pic, what ll be the point of application of force to disengage the brake(it is holding type brake). It is an assignment problem in machine drawing class, I have calculated the shoe dimensions, but I have no idea where ll the force be applied to disengage the brake. And...

I know that in a hydraulic system, oil is used rather than water because water can easily vaporised under extreme use. What the is the advantage/s of using oil over air in a hydraulic system?

Hey - I am a bike mechanic with a large interrest in physics. I know that a larger disc brake rotor provides a greater braking effectiveness, but how can you mathmatically prove it by using physics formulas? And what formulas would be useD? Any ideas would be highly appriciated!

Hi, I have the following formula: brake power = 2(pi)NT I also have the following figures: RPM (instant) = 3550rpm and N° of cycles over 30secs = 880. The engine is four stroke-one cylinder. Just wondering how do I covert the number of cycles to RPM? I have divided by 0.5 because it was for...

How is the braking energy tuned into electrical energy.

Greetings all! There is a bit of a debate in the world of mountain bikes, concerning the conventional 26" wheel diameter versus the rising popularity of the 29" wheel size (nominal diameters). One of the popular beliefs is that the 29" wheel requires a larger brake rotor than a 26" wheel...

Hello All, Can anyone let me know about the 1. Brakepad material and its specific heat 2. Heat dissipation rate, when a brake pad rubs against the rim. 3. Material of rim and its specific heat 4. A method to design the brake system and force required to apply on the brake pedal...

Homework Statement The area of the piston in the master cylinder is 1.8cm^2, and that of the piston in the brake cylinder is 6.4cm^2. The coefficient of friction between shoe and wheel drum is .50. If the wheel has a radius of 34cm, determine the frictional torque about the axle when a force...

My professor went over this but forgot how he explained it. Basically he said if you're in a car and have a wall stretching for miles ahead of you what would be better to do brake or swerve? He wrote something down about how cornering takes place at a rate of something and that braking...

I bought another car, a good Chevy Lumina. Not much wrong with it. But the brake caliper doesn't want to come off. It looks like a mess. I'd prefer to buy a new caliper, but my dad says it'll be fine once we get it off and work at it. I'm not confident in him because he doesn't even want to...

I have begun modelling a basic braking system in Simulink/Matlab for my final year project. The model is designed from the time force is exerted to the pedal at a particular velocity, to when heat is produced from the frictional force between the brake pad and disc. I have the modelling...

Hi all, My model of a car brake system is intended to monitor the rate at which heat increases/decreases as friction between a brake pad and disc increases. My equation for the force transmitted to the disc is: Force = (δP x Ac) x μb where δP is the pressure generated at the master...

Hi all, Im a Mech Eng student getting my 3rd year project underway, Using a simple ABS Disc Brake system model, i would like to analyse braking performance for calculations obtained with variations of brake pad size, mateial, and also different disc sizes and materials. My question...

Homework Statement Driving home from school one day you spot a ball rolling out into the street (Figure 5-18). You brake for 1.15 s, slowing your 1020 kg car from 16.0 m/s to 9.50 m/s. a) What was the average force exerted on your car during braking? Magnitude _____ kN (b) How far...

I,m trying to do some bike customization and would like to modify my mirrors to have a set of led sequential turn signals on them. You can buy modulators to do this for you but i imagine all it is just a couple cappacitors and resitors pretty much that's involved. I am not a electrical idiot and...

Hi all, (this has originally been in the Materials and Chemical Section. I think it does not belong there). I'd like to add a question heat dissipation from a brake bad. Basically, let's assume a brake pad is pressed against a surface that quickly moves along (can be the bicycle brake pad...

I am designing a bike frame and what to know how to calculate the heat generated between the brake pads and the rim. I am wondering if anyone knows of any general equations I can use?

I am designing a bike frame and I want to know how much heat will be generated between the rubber brake pads and the alloy rims. I have looked endlessly on the internet for formulas and I came here hoping someone could give me an answer. I am not looking for a definite answer at this point...

Why is it harder to slow a car down when the brakes are hot? Is there less friction between pads and disc? Is it harder to remove bits of pad material which can carry away kinetic energy?