Question

A constant retarding force of 100 N is applied to a body of mass 20 kg moving initially with speed 25 m/s. How long does the body take to stop ?​

Answer 1

Answer:

5seconds

Explanation:

100/20=5m/s^2

=25(5)t

t=25/5

=5

Answer 2

Answer:-

it takes 5 second for body to stop.

Explanation:-

Given:-

Final velocity (v) =0

Initial velocity (u)= 25 m/s

Force( F)= 100 N

Mass of body (m)= 20kg

Solution:-

$\bf{retardation \:(a) = \frac{</u><u>F</u><u>}{m} } \\ \\ \implies \: \frac{100}{20} = 5 \: \: \: \frac{m}{ {s}^{2} } \\ \\ \red{ \bf{now \: using \: first \: equation \: of \: motion}} \\ \\ \implies \bf{ v = u + at} \\ \\ \implies \: \bf{ 0 = 25 + ( - 5)t }\\ \\ \implies \: \bf{5t = 25 }\\ \\ \implies \: \bf{t = 5 \: s}$

Hence, it takes 5 second for body to stop.