Question

alculate the force needed to increase the velocity of 10 kg object from 20 m/s to 40 m/s in 5 sec.​

Answer 1

Given :

• Final Velocity (v) = 40 m/s

• Initial velocity (u) = 20 m/s

• Time Taken = 5 s

• Mass of the object = 10 kg

To find :

The force needed to increase the velocity of the object.

Solution :

We know the force applied is the product of the. mass of the object and acceleration produced by it.

Mathematically :-

⠀⠀⠀⠀⠀⠀⠀⠀⠀$\underline{\bf{F = ma}}$

Where :-

• F = Force
• m = Mass of the body
• a = Acceleration

So , to find the force we need to know both the mass and the acceleration.

To find the acceleration of the body :

By using the first Equation of Motion and substituting the given values in it , we can find the acceleration produced by the body.

$:\implies \underline{\bf{v = u + at}}$

$:\implies \bf{40 = 20 + a \times 5}$

$:\implies \bf{40 - 20 = a \times 5}$

$:\implies \bf{20 = a \times 5}$

$:\implies \bf{\dfrac{20}{5} = a}$

$:\implies \bf{4 = a}$

$:\implies \bf{a = 4\:ms^{-2}}$

Hence, the acceleration produced by the object is 4 m/s²

⠀⠀⠀⠀⠀⠀⠀To find the force exerted :

Using the formula and substituting the values in it, we get :

$:\implies \bf{F = ma}$

$:\implies \bf{F = 10 \times 4}$

$:\implies \bf{F = 40}$

$\therefore \bf{Force = 40\:N}$

Hence, the force exerted by the object is 40 N.