A truck is traveling at 30 m/s on a slippery road.

Question

A truck is traveling at 30 m/s on a slippery road. The driver slams on the brakes and the truck starts to skid. If the coefficient of kinetic friction between the trucks tires and the road is 0.20, how far will the truck skid before stopping?

Answer 1

First we establish the deceleration as a result of friction by multiply the gravitational constant by the coefficient of friction.

a = 0.20*-9.8 = 1.96 m/s^2

Next we find out just how long the truck was sliding for by dividing the initial speed by the magnitude of this deceleration.

T = 30 m/s / 1.96 m/s^2

T = 15.3 seconds

Finally, we plug this time into the position function.

P(T) = 30 m/s * (T) - 0.98*(T)^2

= 30*15.3 - 0.98*(15.3)^2

= 229.6 m. (Answer)

Answer 2

for acceleration = - μg =a Using V² = U² +aS Here a is negative = -μg

Initial speed² = 2a/ Distance

30*30 = 0.2*9.8/distance

distance= 0.2*9.8/900 m