Mechanical energy into thermal energy

In summary, the roller coaster's maximum speed is 4.1m/s and it is 94.5m high at its highest point. The percentage of energy lost to thermal energy due to friction is 8.9%. To find this, we divide the work done by non-conservative forces by the initial energy, which is equal to the kinetic energy at the roller coaster's maximum speed (43.1 m/s) and the gravitational potential energy at its highest point (94.5m). We then multiply this by 100 to get the percentage.
  • #1
anna sung
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Homework Statement


the roller coaster is 94.5m high at its highest point. what is the maximum possible speed of the roller coaster? the roller coaster's actual maximum speed is 4.1m/s.what percentage is lost to thermal energy due to friction?

Homework Equations


Wnc= Efinal-Eintial
the part i didnt get is highlighted in red.
please help me


The Attempt at a Solution


Wnc= Efinal- Eintial
Efinal= Ek
Einitial=Eg
after i got the numbers i said (Wnc/Einitial)*100 to get the percentage. but it did not get me to the answer.
the answer on the book is = 8.9%
and its maximum speed is = 43.1 m/s
 
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  • #2
divide Wnc by the energy that it should've had (with the 43.1 m/s velocity, .5m(43.1)^2)
and then multiply by 100
 

1. What is mechanical energy?

Mechanical energy is the energy that an object possesses due to its motion or position. It is the sum of an object's kinetic energy (energy of motion) and potential energy (energy of position).

2. How is mechanical energy converted into thermal energy?

Mechanical energy can be converted into thermal energy through friction. When two objects rub against each other, their surfaces create friction, which generates heat and converts the mechanical energy into thermal energy.

3. Can mechanical energy be converted into thermal energy without friction?

Yes, mechanical energy can also be converted into thermal energy through compression. When a gas is compressed, the molecules collide with each other, creating heat and converting the mechanical energy into thermal energy.

4. What are some examples of mechanical energy being converted into thermal energy?

One example is using a hand-cranked generator to power a light bulb. As the crank is turned, mechanical energy is converted into electrical energy, which then powers the light bulb. However, some of the mechanical energy is also converted into thermal energy due to friction between the moving parts of the generator.

5. What are the real-world applications of converting mechanical energy into thermal energy?

Some examples of real-world applications include using friction to heat up brake pads and slow down a moving vehicle, using compressed air to power tools and create heat for welding, and using wind turbines to convert wind energy into electricity and heat for homes and buildings.

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