Hey there, this is my post so I hope it does not seem like I am just asking for help without me trying to do work too.(adsbygoogle = window.adsbygoogle || []).push({});

Ok, the kinetic energy of a car is 8 x 10^6 J as it travels along a horizontal road. How much work is required to stop the car in 10s? That is the question and I am not sure about how I can solve it with Power and Work.

I know that Work = ΔE so we would have using kinetic energy

W = (1/2)mvf^2 - (1/2)mvo^2

W = (1/2)m(0m/s)^2 - 8 x 10^6 J

W = 0 - 8 x 10^6 J

W = -8 x 10^6 J

Is that just the answer? What is the 10s for? Is it just extraneous information?

Can someone just make sure I am answering this question correct

A 1,500 kg car travels at a constant speed of 22 m/s around a circular track that is 80m across. What is the kinetic energy of the car?

KE = (1/2)(m)(v)^2

KE = (1/2)(1500kg)(22m/s)^2

KE = 3.6 x 10^5 J

Thank you.

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# Homework Help: Two Power / Work / Energy Questions

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