Question

amount of force needed to move a body of mass 10 g from rest to a distance of 10 cm in 0.2 s is____??
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Answer 1

Given:

Initial velocity of body,u= 0 cm/s

(Since, body is at rest)

Distance covered by body,s= 10 cm

Time taken by body,t= 0.2 s

Mass of body,m= 10 g

To Find:

Amount of force required

Solution:

We know that,

• According to second equation of motion for constant acceleration,

$\orange{\underline{\boxed{\bf{s=ut+\dfrac{1}{2}at^{2}}}}}$

where,

u is initial velocity

a is acceleration

s is displacement

t is time taken

• $\pink{\underline{\boxed{\bf{Force=mass\times acceleration}}}}$

━━━━━━━━━━━━━━━━━━━━━━━━━

Let the acceleration of body be a

So, on applying second equation of motion on body, we get

$\longrightarrow\rm{s=ut+\dfrac{1}{2}at^{2}}$

$\longrightarrow\rm{10=0(0.2)+\dfrac{1}{2}a(0.2)^{2}}$

$\longrightarrow\rm{10=\dfrac{1}{2}a(0.04)}$

$\longrightarrow\rm{10=0.02a}$

$\longrightarrow\rm{0.02a=10}$

$\longrightarrow\rm{a=\dfrac{10}{0.02}}$

$\longrightarrow\rm{a=500\ cm/s^{2}}$

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Let the amount of force required to move given body be F

So,

$\longrightarrow\rm{F=ma}$

$\longrightarrow\rm{F=10\times500}$

$\longrightarrow\rm\green{F=5000\ dyne}$

Hence, the amount of force needed to move a body of mass 10 g from rest to a distance of 10 cm in 0.2 s is 5000 dyne.

Answer 2

$\huge{\pink{A}\blue{N}\purple{S}\orange{W}\red{E}\blue{R}}$

Given:

Initial velocity of body,u= 0 cm/s

(Since, body is at rest)

Distance covered by body,s= 10 cm

Time taken by body,t= 0.2 s

Mass of body,m= 10 g

To Find:

Amount of force required

Solution:

We know that,

According to second equation of motion for constant acceleration,

$\purple{\underline{\boxed{\bf{s=ut+ \frac{1}{2}at^2}}}}$

where,

u is initial velocity

a is acceleration

s is displacement

t is time taken

$\pink{\underline{\boxed{\bf{Force=mass\times acceleration}}}}$

━━━━━━━━━━━━━━━━━━━━━━━━━

Let the acceleration of body be a

So, on applying second equation of motion on body, we get

$s=ut+ \frac{1}{2}at^2$

$\longrightarrow\rm{10=0(0.2)+\dfrac{1}{2}a(0.2)^{2}}$

$\longrightarrow\rm{10=\dfrac{1}{2}a(0.04)}$

$\longrightarrow\rm{10=0.02a}$

$\longrightarrow\rm{0.02a=10}$

$\longrightarrow\rm{a=\dfrac{10}{0.02}}$

$\longrightarrow\rm{a=500\ cm/s^{2}}$

━━━━━━━━━━━━━━━━━━━━━━━━━

Let the amount of force required to move given body be F

So,

$\longrightarrow{F=ma}$

$\longrightarrow\rm{F=10\times500}$

$\longrightarrow\rm\green{F=5000\ dyne}$

Hence, the amount of force needed to move a body of mass 10 g from rest to a distance of 10 cm in 0.2 s is 5000 dyne.

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