Calculating Average Power for a 1500kg Car Going from 0 to 90km/h in 5s

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To calculate the average power required for a 1500kg car to accelerate from 0 to 90 km/h in 5 seconds, the initial speed is converted to 25 m/s. The acceleration is determined to be 5 m/s², leading to a displacement of 62.5 meters using the equation Vf² - Vi² = 2aS. The force is calculated as F = ma, resulting in 7500 N. Average power is then computed using the formula P = Fv, yielding an average power of 93750 W or 125.7 hp. This approach effectively addresses the problem by correctly applying physics principles.
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Homework Statement


A 1500kg car can go from zero to 90km/h in 5.0 seconds. What is the average power required to do this?


Homework Equations



I tried with P=Fv, I don't really know what else to use(

The Attempt at a Solution


First I converted the 90km/h to m/s and got 25m/s/
Then I did F=mg with m=1500 and g=9.81m/s^2
Then I used the equation P=Fv
P=Fv
P=14175 x 25m/s
P=354375W

ANSWER: 93750w OR 125.7 hp.

Any help would be greatly appreciated.
Thanks
 
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bob24 said:


3. The attempt at a solution
First I converted the 90km/h to m/s and got 25m/s/


OK

Then I did F=mg with m=1500 and g=9.81m/s^2

You can't use g hare. Find the acceleration. And then the displacement.
 
rl.bhat said:
bob24 said:


3. The attempt at a solution
First I converted the 90km/h to m/s and got 25m/s/


OK

Then I did F=mg with m=1500 and g=9.81m/s^2

You can't use g hare. Find the acceleration. And then the displacement.


----
Ok I got acceleration=5m/s^2, and then I did Vf^2-Vi^2=2aS and got 62.5 meters for S.
So do I do
F=ma
F=1500 x 5
F=7500 N?
 
Now average power =ForceX average velocity
 
rl.bhat said:
Now average power =ForceX average velocity

Excellent. Thank you very much!
 
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