Question

a body of mass 2 kg is at rest what should be the mangnitude of force which will the body move with a speed of 30 m/s at the end of 1 sec​

Answer 1

Given :

• Final velocity (v) = 30 m/s
• Initial velocity (u) = 0 m/s
• Time (t) = 1 second
• Mass (m) = 2 kg

To find :

• Force (F)

According to the question,

At first we have to find acceleration then we have to find force,

For finding acceleration we will use Newton's first equation of motion,

$\star \boxed{ \sf \red{v = u + at}}$

$\sf \implies{30 = 0 + a \times 1}$

$\sf \implies{30 = 1a}$

$\implies \sf{a = 30 \: m {s}^{2} } \green \bigstar$

So,the acceleration is 30 m/s^2

Now we will calculate the force

$\star \boxed{ \sf \red{F = ma}}$

• F stands for Force
• a stands for Acceleration
• m stands for Mass

$\sf \implies{ 2\times 30}$

$\implies \sf{60 N } \green \bigstar$

So,the force is 60 N

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

First equation of motion

$\boxed {\sf \purple{v = u + at}}$

Second equation of motion

$\boxed{ \sf \purple{{v}^{2} = {u}^{2} + 2as}}$

Third equation of motion

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

Answer 2

Given data:-

• Mass of body = 2 kg
• Initial velocity = 0 m/s
• Final velocity = 30 m/s
• Time = 1 s

To Find: Force to be exerted which can yield such results.

We know,

F = ma

a = (v-u)/t or, v/t (In this case)

Substitution of values:

F = ma

= m(v/t)

or,

F = 2 kg(30 m/s)/(1 s)

= 2 kg (30 m/s²)

= 60 kg m/s²

= 60 N Ans.

Hope it helps! :D