Question 1

A 1700 kg is traveling along a highway at 100 km/hr and skids to a halt. a) How far will the car travel (while skidding) if the coefficient of kinetic friction between the tires and the road is 0.7? b) How many kilojoules of energy is dissipated during this braking? c) What happens to this energy? Where does it go?

Question 2

$\begin{gathered} \uparrow+Fy=0 \\ N-mg=0 \\ N=mg \\ \rightarrow+Fx=ma \\ Ff=-ma \\ But \\ Ff=N\mu_k \\ Ff=mg\mu_k \\ mg\mu_k=-ma \\ Solving\text{ a} \\ a=-g\mu_k \\ \mu_k=0.7 \\ g=9.81\text{ m/s}^2 \\ a=-(9.81\text{ m/s}^2)(0.7) \\ a=-6.91m/s^2 \\ A) \\ To\text{ find x} \\ v_f^2=v_o^2-2ax \\ Solving\text{ x} \\ v_f^2-v_o^2=-2ax \\ x=(v_f^2-v_o^2)/(-2a) \\ v_o=100\text{ }(Km)/(hr) \\ The\text{ velocity must be in m/s} \\ Hence \\ v_o=100(Km)/(hr)\ast(1000m)/(Km)\ast(1hr)/(3600s) \\ v_o=27.8m/s \\ v_f=\text{ 0 m/s} \\ x=((0m/s)^2-(27.8m/s)^2)/(2(-6.91m/s^2)) \\ x=55.92\text{ m} \\ The\text{ car will travel 55.92m} \\ \\ b) \\ The\text{ total energy dissipated is the kinetic energy of the car} \\ K=(mv^2)/(2) \\ K=((1700kg)(27.8m/s)^2)/(2) \\ K=656914J=656.914KJ \\ \text{The total energy dissipated is 656.914KJ} \\ \\ c) \\ The\text{ energy is dissipated by the heat generated by the friction between} \\ \text{the tires and the road.} \end{gathered}$

A 1700 kg is traveling along a highway at 100 km/hr and skids to a halt. a) How far-example-1

A 1700 kg is traveling along a highway at 100 km/hr and skids to a halt. a) How far-example-2

A 1700 kg is traveling along a highway at 100 km/hr and skids to a halt. a) How far-example-3

A 1700 kg is traveling along a highway at 100 km/hr and skids to a halt. a) How far-example-4

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