Tuesday
March 28, 2017

Post a New Question

Posted by on .

2) A car traveling with 5 m/s encounters a deer. The drivers slams on the breaks, the breaks lock. The car
skids to a complete stop on the road ahead (and the deer runs away). Why does the car stop (where does
all the kinetic energy it had go)? Find the magnitude of the friction force if the skid marks show a 20 m slide
and the mass of the car mass is 400 kg.
Here

  • College Physic - ,

    2a. All KE was converted to PE during braking.

    2b. a = (V^2-Vo^2)/2d.
    a = (0-(5)^2) / 40 = -0.625 m/s^2.

    Wc = mg = 400kg * 9.8N/kg = 3920 N. = Wt. of car

    Fc = 3920N @ 0 Deg. = Force of car.
    Fp = 3920*sin(0) = 0 = Force parallel to road.
    Fv = 3920*cos(0) = 3920N. = Force perpendicular to road.

    Fn = Fp - Fk = ma.
    0 - Fk = 400*(-0.625).
    Fk = 250 N. = Force of kineti friction.

Answer This Question

First Name:
School Subject:
Answer:

Related Questions

More Related Questions

Post a New Question