A car of mass 1200 kg, travelling at a steady speed of 15 m/s performs an emergency stop which takes 4.5 seconds. What braking force was applied by the driver and car to achieve this?

4000 N

Step-by-step explanation:

this question should be in physics actually

m = 1200 kg

initial velocity = vo = 15 m/s

final velocity = vt = 0 because it stops

time needed = t = 4.5

so we can find the Force F by these step

first find deacceleration

vt = vo + at

0 = 15 + a (4.5)

15 = - 4.5a

a = - 15/4.5 = - 10/3 = - 3.33 m/s²

F = m. a = 1200. 10/3 = 4000 N