Car accelerating on ramp - power of engine

In summary, the conversation discusses a problem involving a car accelerating up a ramp with a 5 degree angle and the question of what fraction of the power from the engine goes into the car's kinetic energy. The conversation also touches on the concept of power being related to energy per second and the role of potential energy in the problem. The solution involves using kinematics to find the final speed and then calculating the ratio of kinetic energy to the sum of kinetic and potential energy, which results in 54%. It is noted that this method only works if friction and other forces are ignored.
  • #1
physstudent1
270
1

Homework Statement



A car accelerates at 1 m/s^2 up a ramp which makes an angle of 5 degrees with the horizontal. Ignoring friction and air resistance what fraction of the power the engine puts into the car's motion goes into the car's kinetic energy?

Homework Equations





The Attempt at a Solution



I don't know how to attempt this problem I know the answer is 54% because this is a review problem for my test which is coming up, but how is power related to kinetic energy?
 
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  • #2
Power is energy (or work) per second.

Where is the energy from the engine going apart from into kinetic energy, KE?
 
  • #3
some would have to be going into potential energy right? there's no friction or air resistance so nothing else could be taking energy
 
  • #4
well I got to the correct answer I decided to measure the problem after the car had traveled 1 meter, used kinematics to find the final speed then put

KE/(KE+PE) and it worked out because the masses canceled out and i got .538 which is correct will the method always work out if there is no friction or any other forces to worry about. It seems like this isn't the correct way to do it.
 
  • #5
physstudent1 said:
well I got to the correct answer I decided to measure the problem after the car had traveled 1 meter, used kinematics to find the final speed then put KE/(KE+PE)

That's correct, if you ignore friction conservation of energy is always correct - and is often the simplest way to do it.
 

1. How does the power of the engine affect the acceleration of a car on a ramp?

The power of the engine plays a significant role in determining the acceleration of a car on a ramp. The greater the power of the engine, the more force it can generate to move the car forward, resulting in a faster acceleration.

2. What is the relationship between engine power and torque in accelerating a car on a ramp?

The power of an engine is directly related to its torque. Torque is the rotational force that the engine produces, and this force is what propels the car forward. Therefore, the higher the engine power, the higher the torque, and the faster the acceleration on a ramp.

3. Does the weight of the car affect the acceleration on a ramp?

Yes, the weight of the car does affect the acceleration on a ramp. A heavier car will require more power from the engine to overcome its weight and accelerate, while a lighter car will require less power. This is why sports cars, which are typically lighter, have faster acceleration than heavier vehicles.

4. Can the type of fuel used in a car's engine affect its acceleration on a ramp?

Yes, the type of fuel used in a car's engine can have an impact on its acceleration on a ramp. Premium fuels, which have a higher octane rating, can provide more power and better performance compared to regular fuels. This can result in a faster acceleration on a ramp.

5. How does the design of the ramp impact the acceleration of a car?

The design of the ramp can affect the acceleration of a car in several ways. A steeper ramp will require more power from the engine to overcome the force of gravity and accelerate, while a gentler slope will require less power. Additionally, the length of the ramp can also impact acceleration, as a longer ramp allows for more time for the car to gain speed.

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