Answer:
F = 7.143 kN
Explanation:
given,
time taken to apply break = 1.05 s
car slows down from 15 m/s to 9 m/s
mass of the car = 1250 Kg
force is equal to the change in momentum with respect to time.
[tex]F = \dfrac{\Delta P}{t}[/tex]
[tex]F = \dfrac{m(v_f - v_i)}{t}[/tex]
[tex]F = \dfrac{1250\times (9 - 15)}{1.05}[/tex]
[tex]F = \dfrac{-7500}{1.05}[/tex]
F = -7142.85 N
F = - 7.143 kN
Force is acting opposite direction of velocity of car i.e. the sign is negative.