What average force is required to stop a 1900 kg car in 9.0 s if the car is traveling at 95 km/h ?

Acceleration, a = -F/m = -F/1900 m/s²
Initial velocity, u = 95 km/h = (95 × 1000 m) / (3600 s) = 26.4 m/s
Final velocity, v = 0 m/s
Time taken, t = 9.0 s

v = u + at
0 = 26.4 + (-F/1900) × 9.0
9.0F/1900 = 26.4

Average force required, F = 26.4 × (1900/9) N = 5600 N

Given,

Mass of the car (m) = 1900kg

Time (t) = 9sec

Final velocity (v) = 95km/hr = 26.3889m/sec

Average force (Farg) =?

Initial force (u) = 0m/sec

Impulse-Momentum theorem:-

It states that the change in momentum of an object equals the Impulse applied to it If Mass is constant,

Impulse=change in momentum

Force*time = m (∆V)

Force = m (v - u)/t = 1900(26.3889 - 0)/9

Force = 1900*26.3889/ 9

= 5570.99N

Average force (Farg) = 5571N