Question

A 1500kg car travels north with a speed of
$8m {s}^{ - 1}$
It slows down to a speed of
$2m {s}^{ - 1}$
in 3 seconds. Find the acceleration and the force exerted on the car during this time.​

Answer 1

Explanation:

[07/10, 12:14]

[07/10, 12:14]

[07/10, 12:14]

Answer 2

Given:

Mass of car = 1500 kg

u = 8 m/s

v = 2 m/s

t = 3 s

To find:

Acceleration of the car and force exerted on the car.

Solution:

$\sf a=\dfrac{v-u}{t}$

$\sf a=\dfrac{2-8}{3}$

$\sf a=\dfrac{-4}{3} m/s^{2}$

F = ma     - 2nd law of motion

F = $\sf 1500 \times (-\dfrac{4}{3} )$

F = -500*4

F = -2000 N

Answers:

Acceleration of the car is $\sf\dfrac{-4}{3} m/s^{2}$ (or retardation = $\sf\dfrac{4}{3} m/s^{2}$) and force exerted on the car is -2000 N (braking force hence it has negative sign; opposite to the direction of motion.)