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Question

o Secure l https lloutlook ive.com/owanrealmehotmailcom&paths;/attachmentlightbox utlook Mail 8. (10 points) stopping Distance. A car is traveling on level road with speed v the instant when the brakes lock, so that the tires slide rather than work roll. (a) Use the energy theorem calculate the minimum stopping distance of the car in g terms of v 0, and the coefficient of kinetic friction between the tires and the road. (b) By what factor would the minimum stopping distance change if (i the coefficient of kinetic friction were doubled, or (ii) the initial speed re doubled, or (iii) both the coefficient of kinetic friction and the initial speed were doubled?

Explanation / Answer

By work energy theorem

Work done by friction=change in kinetic energy

mu _k*mg*distance =0.5*m*v_0*v_0

So we got

Distance=v_0*v_0/(2g*u_k)

(b)if coefficient of friction is doubled, distance will be halved.so change by factor 1/2

If initial speed if doubled,distance will increase 4 times

If both are doubled, distance will increase 2 times