The accident occured on a rainy day, and the coeffient of kinetic friction was estimated to be 0.42. Use these data to determine the speed of the car when the driver slammed on (and locked) the brakes. (why does the car's mass not matter?)
2006-11-11 05:30:15 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Physics
You don't need the mass, just multiply u*g, to calculate the deceleration. After that use this equation:
2*a*d = Vo^2, where a=u*g, u=coefficient of friction, g= gravity acceleration.
Vo initial velocity, then
Vo= sqrt(2*a*d) maybe the velocity was greater than that value.
I hope this is useful for you.
2006-11-11 08:54:50 · answer #1 · answered by jaime r 4 · 0⤊ 0⤋
You do an energy-work balance. The mass on both sides of the equation cancel out.
2006-11-11 21:34:50 · answer #2 · answered by Stan the Rocker 5 · 0⤊ 0⤋
the work = mass*acceleration*distance represented by the skid mark is equal to the kinetic energy of the car.
Set the two equal; what can you do with the mass?
2006-11-11 13:42:07 · answer #3 · answered by arbiter007 6 · 0⤊ 0⤋
They're trying to determine the driver's reflexes like was he slowed down by the Demon Rum?
2006-11-11 13:37:41 · answer #4 · answered by robert m 7 · 0⤊ 0⤋