Question

a constant force is applied for 2s on a body of mass 5kg.as a result,if the velocity of the body is changed from 3m/s to 7m/s find the value of the force applied​

Answer 1

Given :

• Intial velocity = 3 m/s.

• Final Velocity = 7 m/s.

• Mass of the body = 5 kg.

• Time = 2 s

To find :

Force applied by the body.

Solution :

First' let us find the Acceleration produced by the body .

We know the first Equation of Motion i.e,

⠀⠀⠀⠀⠀⠀⠀v = u + at

Where :

• v = Final Velocity
• u = Intial velocity
• a = Acceleration
• t = Time Taken

Using the first Equation of Motion and substituting the values in it, we get :

==> 7 = 3 + a(2)

==> 7 - 3 = 2a

==> 4 = 2a

==> 4/2 = a

==> 2 = a

∴ a = 2 m/s²

Hence the Acceleration produced by the body is 2 m/s².

Force applied :

We know the formula for force i.e,

⠀⠀⠀⠀⠀⠀⠀F = ma

Where :

• F = Force
• m = Mass
• a = Acceleration

Now by using the Equation for force and substituting the values in it, we get :

==> F = ma

==> F = 5 × 2

==> F = 10

∴ F = 10 N

Hence the force exerted by the body is 10 N.