Question

A 2200 kg car traveling at 25 m / s [S] stops in 10 s.

Determine:
the acceleration of the car;
the net force required to produce this acceleration.

Answer 1

Answer:

$-2.5\ \text{m/s}^2$

$-5500\ \text{N}$

Explanation:

m = Mass of car = 2200 kg

t = Time = 10 s

v = Final velocity = 0

u = Initial velocity = 25 m/s

a = Acceleration

From the kinematic equations of linear motion we have

$v=u+at\\\Rightarrow a=\dfrac{v-u}{t}\\\Rightarrow a=\dfrac{0-25}{10}\\\Rightarrow a=-2.5\ \text{m/s}^2$

Acceleration of the car is $-2.5\ \text{m/s}^2$

Force is given by

$F=ma\\\Rightarrow F=2200\times (-2.5)\\\Rightarrow F=-5500\ \text{N}$

Net force required to produce the acceleration is $-5500\ \text{N}$.