Question

how long will it take a force of 10N to stop a mass of 2.5 kg which is moving with 20m/s ?

Answer 1

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$\large \star{\tt{\blue{Given:-}}}$

${\tt{Mass= 2.5 kg = 2500 g}}$

${\tt{Acceleration = 20m/s^2}}$

${\tt{Force = 10N}}$

${ \huge{ \bold{\underline{ \underline{ \orange{Concept:-}}}}}}$

Thus, the force is the cause and the acceleration is the effect of it. When a force F is applied to a body produces an acceleration a in it, then from Newton's law.

${ \huge{ \bold{\underline{ \underline{ \blue{Formula \: used:-}}}}}}$

${\tt{Force = Mass × Acceleration}}$

${\tt{F =ma}}$

NoW,

${\tt{10N = 2500 × 20}}$

${\tt{10N = 50,000}}$

${\tt{N = 5000 F}}$

$\leadsto\huge\underline{\underline{\boxed{\mathtt{\color{pink}{5000 F}}}}}{\color{orange}{\bigstar}}$

Answer 2

Answer:

force applied(F)= -10N (since the force is acting in the opp. direction of motion or opposing the motion)

mass of body(m)=2.5kg

initial velocity of body(u)=20m/s

final velocity of body(v)=0m/s

According to newton's seond law of motion

F=ma

-10=2.5*a

-10/2.5=v-u/t (since a=v-u/t)

-4t=0-20

t=-20/-4

t=5 sec.