A constant force acting on a body of mass 3 kg changes its speed from 2 m/s to 3.5 m/s in 25 s. The force exerted is
Answers
Explanation:
m = 3kg, u = 2m/s, v = 3.5m/s and t = 25s.
Using the equation v = u+at, we get a = v-u/t
By substituting we get a= 0.06m/s².
So F = ma,
F = 3×0.06 = 0.18N.
Answer :
- The force exerted on the body of mass 3kg which changes its speed from 2 m/s to 3.5 m/s in 25 s, F = 0.18 N.
Explanation :
Given :
- Mass of the body , m = 3 kg
- Initial velocity of the body, u = 2 m/s
- Final velocity of the body, v = 3.5 m/s
- Time taken in ∆ Velocity = 25 s
To find :
- Force exerted on the body, F = ?
Knowledge required :
- By definition , Force is the product of the mass of the body and the change in velocity.
So,
⠀⠀⠀⠀⠀⠀⠀⠀⠀F = m∆v
We know that , ∆v (change in velocity) is the Acceleration produced by a body .
Hence,
⠀⠀⠀⠀⠀⠀⠀⠀⠀F = ma
Where :
- F = Force exerted
- m = Mass of the body
- a = Acceleration produced by the body
- First equation of motion :
⠀⠀⠀⠀⠀⠀⠀⠀⠀v = u + at
Where :
- v = Final velocity
- u = Initial velocity
- a = Acceleration
- t = Time taken
Solution :
First let us find the Acceleration of the body :
Using the first equation of motion and substituting the values in it, we get :
==> v = u + at
==> 3.5 = 2 + a × 25
==> 3.5 - 2 = 25a
==> 1.5 = 25a
==> 1.5/25 = a
==> 0.06 = a
∴ a = 0.06 m/s²
Hence the accelaration produced by the body is 0.06 m/s².
Force exerted by the body :
Using the equation for force and substituting the values in it, we get :
==> F = ma
==> F = 3 × 0.06
==> F = 3 × 6/100
==> F = 18/100
==> F = 0.18
∴ F = 0.18 N
Therefore,
- The force exerted by the body is 0.18 N.