Kinetic Energy problem i think

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SUMMARY

The discussion centers on calculating the kinetic energy required to accelerate a car from 10-20 m/s versus 20-30 m/s using the formula KE = 1/2mv². The calculations show that the change in kinetic energy for the first interval (10-20 m/s) is 150 joules, while for the second interval (20-30 m/s), it is 250 joules. Thus, accelerating from 20-30 m/s requires an additional 100 joules of energy compared to the first interval. This conclusion is based on the principle of conservation of energy.

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nlsed
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Homework Statement



What takes more energy? Accelerating a car from 10-20m/s or from 20-30m/s? Why?

Homework Equations





The Attempt at a Solution



Since KE = 1/2mv^2, I suppose the higher the velocity is the more kinetic energy the car will have, but I have no clue how to solve this problem.
 
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Won't the bigger change in kinetic energy require the greater energy?
You know that conservation of energy thing?

Plug in the numbers.
 
then change in kinetic energy equals the work done, which one requires more work?
 
so is this right? since m is constant it is just 1kg

1/2mv2
1/2(1kg)(10m/s)2 = 50 joules
1/2(1kg)(20m/s)2 = 200 joules
1/2(1kg)(30m/s)2 = 450 joules

KE for (10-20m/s) = 150 joules
KE for (20-30m/s) = 250 joules

So accelerating from 20-30m/s requires 100 more joules of energy?
 
Last edited:
nlsed said:
So accelerating from 20-30m/s requires 100 more joules of energy?

That should do it.
 
Thank you very much! :!)
 

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