Question

A force acting for 5 seconds on a body of mass 2.0 kg initially at the rest force is there withdrawn and the body moves with a velocity of 2 metre per second minus find the magnitude of force
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Answer 1

Given :

• Initial velocity (u) = 0 m/s
• Final velocity (v) = 2 m/s
• Time (t) = 5 seconds
• Mass (m) = 2.0 kg

To find :

• Force (F)

According to the question,

$\sf \implies{ \fbox {\sf \red{v = u + at}}} \\ \\ \implies \sf{2 = 0 + a \times 5} \\ \\ \sf \implies {2 - 0 = 5a} \\ \\ \implies \sf{2 = 5a} \\ \\ \sf \implies {a = \frac{2}{5} } \\\\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \implies \sf{a = 0.4 \: {ms}^{2} } \green \bigstar$

Now we will find the force,

$\implies{ \fbox{ \sf \red{F= ma}}} \\ \\ \implies \sf{2 \times 0.4} \\ \\ \implies \sf{0.8 \: N} \green \bigstar$

So,the force is 0.8 N..

__________________....

Other equation of motion :-

$\bullet \: \sf{v = u + at} \\ \\ \bullet \: \sf{s = ut + \frac{1}{2} {at}^{2} } \\ \\ \bullet \: \sf{ {v }^{2} = {u}^{2} + 2as}$

• u stand for Initial velocity
• v stands for Final velocity
• t stands for Time
• a stands for Acceleration
• s stands for Distance

Answer 2

• Given

• Initial velocity (u) = 0 m/s
• Final velocity (v) = 2 m/s
• Time (t) = 5 seconds
• Mass (m) = 2.0 kg

• To find

• Magnitude of force

• Solution

• Firstly, for finding force we need acceleration.

$\implies$ v = u + at

$\implies$ 2 = 0 + a × 5

$\implies$ 2 = a × 5

$\implies$ a = 0.4 m/s²

• $\red{\bigstar}$Acceleration = 0.4 m/s²

Formula to find force -

$\implies$ F = ma

Substitute the given values.

$\implies$ F = 2 × 0.4

$\implies$ F = 0.8 N

• Force = 0.8 N