Question

a car of mass 2000kg changes its speed from 72km/h to 36km/h in 5 seconds the force applied by the brake is ?​

Answer 1

Answer:

-4000 N

Explanation:

m = 2000 kg

u = 72 km/h = 72 x $\frac{5}{18}$ = 20 m/s

v = 36 km/h = 36 x $\frac{5}{18}$ = 10 m/s

t = 5 s

m = 2000 kg

F = ma

a = $\frac{v-u}{t}$

a= $\frac{10-20}{5}$

a = $\frac{-10}{5}$

a= -2 $\frac{m}{s^{2}}$

F = -2 x 2000

F = -4000N