4. Page  3  Brakes are devices whose function it is to slow and stop and automobile. They are mandatory for the safe operation of vehicles.  Brakes have been refined and improved ever since their invention. The increase in traveling speeds as well as the growing weights of cars have made these improvements essential.  An effective braking system is needed to accomplish this task. Today's cars often use a combination of disc brakes and drum brakes.  Disc brakes are usually located on the front two wheels and drum brakes on the back two wheels.

5.  Brakes operate by converting the kinetic energy (motion) of an automobile into heat energy. How effectively this is achieved depends on the type of braking system.  Disc brakes operate in a similiar fashion to that of a bicycle. It involves pushing a block against a spinning wheel. This contact causes friction, which changes kinetic energy into heat energy.  Drum brakes have their blocks located in the inside of a drum. Like the disc in disc brakes, the drum are attached to the wheels. When the brake pedal is pressed then it causes friction which turns kinetic energy into heat energy, thus slowing the car. Page  4

6.  Improvements in materials (wood blocks to cast iron brake shoes) Page  5

7.  The 20th century brought many advances to the types of braking. As the automotive and trucking industries developed, brake systems improved. Early automobiles had band brakes which were then followed by drum brakes; both were applied mechanically through linkage.  However, much like the drum brakes, the design flaw of the disc brake is its limited thermal mass. Every time you apply the brakes, the mass increases in temperature. This can be demonstrated by modern race cars, whose brakes glow red-hot during races. When brakes get hot, the stresses increase and performance fades. Page  6

8. Page  7  You might have observed forward push when bus suddenly starts. Lift gives upward push when it starts. This is what acceleration is! Here Velocity changes. Hence the body accelerates.  Acceleration is the rate of change in velocity to the change in time. It is represented by symbol a and is given by  The S.I unit for Acceleration is meters per second square or m/s2.

9. Page  8  If initial velocity u, final velocity v time taken t are given. Then the acceleration is given by formula where : v = Final Velocity, u = Initial velocity, a = acceleration, t = time taken, s = distance traveled.

10. Page  9  The total braking force required can simply be calculated using Newton’s Second Law.  Can be applied when stopping the vehicle

11.  In order to calculate the power we need to know the brake on time:  The power is then given by: 10

12. 11 Thank You ZikZieq Make Engineering much more fun Cooperate Partner : Muhammad Khaziq bin Sazali Muhammad Zikri Rafi’uddin bin Mohd Zahidi