Question

velocity.
body of mass 0.25 kg moving with velocity 12 m/s is stopped by applying a force of 0.6 N. Calculate
time taken to stop the body. Also calculate the impulse of this force.​

Answer 1

AnSwEr:–

$\longrightarrow$ Time taken = 5 seconds

$\longrightarrow$ Impulse= -3 Ns

SteP By SteP ExplainaTion:–

• mass,m= 0.25 kg

• initial velocity,u= 12 m/s

• Final velocity,v=0 m/s

• Force,F= -0.6 N

(negative sign shows that the force is in opposite direction of the body )

First we find the acceleration;

$\longrightarrow \:{ \tt{ a = \frac{F}{m} }} \\ \\ \\ \longrightarrow \: { \tt{a = \frac{ - 0.6}{0.25} }} \\ \\ \\ \longrightarrow \:{ \bf{ a = - 2.4 \: ms {}^{ - 2} }}$

Now, using first equation of motion,

$\longrightarrow \: \tt{v = u + at} \\ \\ \\ \longrightarrow \tt{0 = 12 + ( - 2.4)t} \\ \\ \\ \longrightarrow \tt{ \frac{ - 12}{ - 2.4} = t} \\ \\ \\ \longrightarrow \: { \boxed{ \bf{t = 5 \: s}}}$

Now, we find Impulse of this force;

$\longrightarrow\tt{I= F × t}$

$\longrightarrow\tt{I=-0.6×5}$

$\longrightarrow\boxed{\bf{I=-3\:Ns}}$

Answer 2

||✪✪ GIVEN ✪✪||

• Mass of Body = 0.25kg.
• Velocity = 12m/s.
• Force Applied = 0.6N

|| ★★ To Find ★★ ||

• Time Taken to Stop The body .
• Impulse of Force.

|| ✰✰ ANSWER ✰✰ ||

Given That :-

→ Mass = 0.25kg.

→ Force = F = (-0.6N) { In opposite Direction).

Now, According to Newton's Second Law of Motion we know That, Force = Mass * Acceleration .

So,

→ F = m * a

→ (-0.6N) = (0.25) * a

→ a = (-0.6N) / (0.25)

→ a = -2.4ms^(-2) .

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Now, we Have :-

→ Initial velocity = u = 12m/s.

→ Final velocity = v = 0 . ( As Stopped).

→ a = -2.4ms^(-2)

Now, using First Equation of Motion v = u + at, we get :-

→ 0 = 12 + (-2.4) * t

→ 2.4t = 12

→ t = (120/24)

→ t = 5 seconds.

Hence, Time Taken to Stop the body is 5 seconds.

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Now , we Have to Find impulse of This force ?

Impulse is the change of momentum of an object when the object is acted upon by a force for an interval of time.

→ I = F * t

→ I = (-0.6) * 5

→ I = (-3)N.s

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