Calculating Thermal Energy Dissipated from Brakes on a Descending Car

• Stryder_SW
In summary, the proper design of automobile braking systems must consider heat buildup during heavy braking. To calculate the thermal energy dissipated from brakes in a 1260-kg car descending a 18.5° hill, the work-energy theorem can be used by equating the work done by the brakes to the mechanical energy lost. This can be determined by considering the potential and kinetic energy involved in the car's descent.
Stryder_SW

Homework Statement

Proper design of automobile braking systems must account for heat buildup under heaving braking. Calculate the thermal energy dissipated from brakes in a 1260-kg car that descends a 18.5° hill. The car begins braking when its speed is 102 km/h and slows down to a speed of 34 km/h in a distance of 0.51 km measured along the road.

I honestly have no idea how to do this.

Think about how much potential energy as well as kinetic energy must be accounted for by the work of breaking over that distance.

Hi Stryder_SW!

Virtually all the mechanical energy lost goes into heat (thermal energy), so …

Hint: use the work-energy theorem … work done by the brakes = mechanical energy lost.

1. How do car brakes work?

Car brakes work by applying friction between the brake pads and the brake rotor, creating resistance and slowing down the rotation of the wheels. This friction converts kinetic energy into thermal energy, which is then dissipated through the brake components.

Brake fade is caused by the build-up of heat in the brake components, which decreases the friction between the brake pads and rotor. This can be caused by continuous or heavy use of the brakes, or by worn brake pads and rotors.

3. What is the role of thermal energy in car brakes?

Thermal energy is essential in car brakes as it is the energy that is converted from kinetic energy to slow down the car. It is also responsible for dissipating the heat generated during braking to prevent brake fade and maintain the effectiveness of the brakes.

4. How do different driving conditions affect thermal energy in car brakes?

Driving conditions such as heavy traffic and steep hills can increase the amount of thermal energy generated in car brakes due to frequent and prolonged use. On the other hand, driving at high speeds on a highway can also generate a significant amount of thermal energy due to the higher speed and friction.

5. How can I prevent excessive thermal energy in my car brakes?

To prevent excessive thermal energy in your car brakes, it is important to properly maintain your brakes by regularly checking and replacing worn brake pads and rotors. Additionally, avoid harsh and continuous braking and allow your brakes to cool down between uses. Upgrading to high-performance brake components can also help dissipate heat more efficiently.

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