Answer
given,
mass of the car = 2510 Kg
angle of inclination = 10°
initial speed = v₁ = 20 m./s
skid length = 20 m
coefficient of friction = 0.5
Using conservation of energy
[tex]\Delta E = \Delta KE + \Delta U[/tex]
[tex]\Delta E = \dfrac{1}{2}mv^2 + m g h[/tex]
h = d sin θ
[tex]\Delta E = \dfrac{1}{2}mv^2- m g (dsin\theta)[/tex]
[tex]\Delta E = \dfrac{1}{2}\times 2510 \times 20^2- 2510\times 9.8 \times (20 sin10^0)[/tex]
[tex]\Delta E =416572.04\ J[/tex]
now, calculating the magnitude of frictional force is equal to
E = F_f d
[tex]F_f = \dfrac{E}{d}[/tex]
[tex]F_f = \dfrac{416572.04}{20}[/tex]
[tex]F_f = 20828\ N[/tex]
