Engine Performance(Finding Power)

In summary, a car manufacturer claims that their car can accelerate from rest to 101 km/hr in 5.6 seconds with a mass of 840 kg. To determine the power developed by the car's engine, the conversation discusses converting the speed to m/s and using the equations V=Vo + at and P=F*v. It is then mentioned that the power is constant and the acceleration may not be, leading to a discussion on how to incorporate that into the equation. The conversation concludes with the use of the equation P=W/t and the concept of constant power. It is noted that Fv is constant and this leads to the conclusion that work is equal to the change in kinetic energy.
  • #1
austin zitro
5
0
Ok, here is the problem:
A car manufactuerer claims that their car can accelerate from rest to 101 km/hr in 5.6 seconds. The car's mass is 840 kg. Assuming that this performance is achieved at constant power, determine the power developed by the car's engine.
Part B) What is the car's speed after 2.8 s?

Ok, so first off i changed the 101km/hr to m/s. So it should be 28.1m/s. Then I used the equation: V=Vo + at to find acceleration and so plugging in 28.1m/s=0 + a(5.6s), a= 5.01m/s^2. So since power = F*v, I plugged in P = 840kg*5.01m/s^2*28.1 = 118256.04 W. This is not right. Since the power is constant, I'm thinking that the acceleration is probably not. So how would I incorporate that into my equation?? Once I get that, I can prolly get part B. Thank's for any help at all!
 
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  • #2
Check those units are those the Power units?? also think about constant power what does that mean?
 
  • #3
I ended up getting it. I used the equation P=W/t, where work = change in kinetic energy. Thanks for the help.
 
  • #4
You know that
[tex]F = m \frac {dv}{dt}[/tex]
What can you conclude if Fv is constant?
 

What is engine performance?

Engine performance refers to the ability of an engine to produce power and efficiently convert fuel into mechanical energy.

How is engine performance measured?

Engine performance is measured by various factors such as horsepower, torque, acceleration, and fuel efficiency. These measurements can be taken using dynamometers and other performance testing equipment.

What factors affect engine performance?

Several factors can affect engine performance, including the design and condition of the engine components, the type and quality of fuel used, and the operating conditions such as temperature and altitude.

What are some ways to improve engine performance?

There are several ways to improve engine performance, such as upgrading engine components, using higher octane fuel, and optimizing the engine's air-fuel ratio. Regular maintenance and tuning can also help improve performance.

How can engine performance be optimized for a specific purpose?

Engine performance can be optimized for a specific purpose by modifying certain components, such as installing a high-performance camshaft or changing the exhaust system. Tuning and adjusting the engine's parameters can also help achieve the desired performance for a specific purpose.

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