Question

solve it.....,......... ​

Answer 1

Given:-

• Mass of object,m= 5 kg
• Time taken by object,t= 2s
• Initial velocity of object,u= 3 m/s
• Final velocity of object,v= 7 m/s

To Find:-

• The magnitude of the applied force and the velocity of object if the force is applied for a duration of 5s

Solution:-

We know that,

• Acceleration of a particle 'a' is given by

$\pink{\underline{\boxed{\bf{a=\frac{v-u}{t}}}}}$

Expression of force F is given by

$\purple{\underline{\boxed{\bf{F=ma}}}}$

where,

• v is final velocity
• u is initial velocity
• t is time taken
• m is mass

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Let the acceleration of object be a

So,

$\longrightarrow\rm{a=\dfrac{v-u}{t}}$

$\longrightarrow\rm{a=\dfrac{7-3}{2}}$

$\longrightarrow\rm{a=\dfrac{4}{2}}$

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

Let the applied force be F

So,

$\longrightarrow\rm{F=m\times a}$

$\longrightarrow\rm{F=5\times 2}$

$\longrightarrow\rm\green{F=10\ N}$

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Let the final velocity of second case be v'

So,

$\longrightarrow\rm{a=\dfrac{v'-u}{t}}$

$\longrightarrow\rm{2=\dfrac{v'-3}{5}}$

$\longrightarrow\rm{10=v'-3}$

$\longrightarrow\rm{v'-3=10}$

$\longrightarrow\rm\green{v'=13\ m/s}$

Hence, the applied force is 10 N and the velocity of object if the force is applied for a duration of 5s  is 13 m/s.