00:01
So here, the initial velocity of the car is increased by 50 % and we're trying to find how the, by what factor does the minimum braking distance change? so we can say that if the mass of the car, mass of m, we can draw a free body diagram for the car.
00:21
So going straight down is the force of gravity.
00:24
Going straight up would be force normal.
00:27
And going straight to the left would, of course, be force of friction.
00:32
We could say that the work needed in order to, the work needed in order to stop the car would be its change in kinetic energy.
00:44
And then we also know that the force of friction is going to be equal to the coefficient of kinetic friction times the normal force.
00:52
And then we can say that the sum of forces in the y direction equals zero, which means that the force normal minus the force of gravity equals zero.
01:03
Giving us that the force normal equals the force of gravity.
01:08
So at this point, we can say that the only force in the x direction that would be affecting work.
01:16
So force would be the only force, a force of friction would be the only force that is parallel to the distance, to the displacement of the car...