Hey guys I was wondering if any of you know how to solve this physics problem about forces. Any help ASAP would be greatly appreciated :)
Joe drives his 1600 kg car to work at a speed of 108 km/h (30 m/s). When the road is dry, the coefficient of kinetic friction between the pavement and the tires on his car is 0.80. When the pavement is wet, the coefficient of kinetic friction is 0.50. Determine how much farther it takes his car to come to an emergency stop when the pavement is wet than when it is dry.
??
2007-04-19 16:09:49 · 2 answers · asked by Shaun S 1 in Science & Mathematics ➔ Physics
The maximum decelerating force on the car is
a = gKk where g is gravity (9.8 m/s²) and Kk is the coefficient of kinetic friction. The velocity of an object after decelerating x meters with deceleration a and initial velocity V0 is
V² = V0²-2ax. Since V will be 0 when the car stops
x = V0²/(2a) and now it's just plug 'n play. You do the arithmetic ☺
HTH
Doug
2007-04-19 16:22:48 · answer #1 · answered by doug_donaghue 7 · 0⤊ 0⤋
There are several steps to this problem.
First you need to find the acceleration of the car on both the wet and dry road. Remember that F(friction)=-C*F(normal), where C is the coefficient of friction.
Once you have a, you can use v-vo=at to find the time it take the car to stop.
Finally use x-x0=1/2at^2+vot to find the distance traveled.
2007-04-19 16:18:41 · answer #2 · answered by sparrowhawk 4 · 0⤊ 0⤋
Force equals mass times acceleration
2007-04-19 16:12:05 · answer #3 · answered by Rachel T. 2 · 0⤊ 0⤋