Question in physics, dont remeber how to solve without using energy equations?

Question

.A car with a mass of 2400kg is driving along at 23m/s. It hits its breaks and skids to a stop. The coefficient of kinetic friction is 0.41, how far does it travel?

Can I just take the force of friction and divide by the mass to get the acceleration in the opposite direction and solve from there?

Answer 1

Yes you're on the right track, you know the momentum of the car along with the energy, both are conserved.

Force=Mass*Acceleration=Coefficient of Friction*Mass*Gravity

You can then solve for Acceleration=Coefficient of Friction*Gravity
Velocity=Acceleration*t
Then its simply a matter of filling t into this equation:
Distance=1/2*Acceleration*t^2+Velocity*t

Answer 2

Since the car is traveling horizontally you can solve for the acceleration directly.

The force due the friction factor applies to the Normal force of the cars weight. Mass x g

You can do the math but the mass terms cancel out and you'll be left with a negative acceleration of 0.41xg

Then use the equation of the previous answer to calculate the distance.

Answer 3

permit sparkling up via winding up the sq. x^2 - 4x + one million = 0 x^2 - 4x + 4 + one million - 4 = 0 (x - 2)(x - 2) - 3 =0 (x - 2)^2 - 3 = 0 (x - 2)^2 = +3 {(x - 2)^2} = +/- { 3 } x - 2 = +/- { 3 } x = +/- { 3 } + 2 the place { sq. root }