Question

A force of 10N is acting on an
object of mass 5kg to change
its velocity from 10m/s to
30 m/s. Find the work done​

Answer 1

Answer:

25N

Explanation:

Given Data:-

m= 5kg

Vi= 10 m persecond

Vf= 0

Time= 2s

Required:- F=?

Solution:-

First of all. To find acceleration we use first equation of motion.

a= vf - vi/ t

a= -5 m persecond square

Now Using Newton's second law of motion.

F= ma

F= -25N. The negative sign indicate that the force required to stop the body would be opposite to direction of the body.

Answer 2

Answer :

Magnitude of applied force = 10N

Mass of body = 5kg

Initial velocity = 10m/s

Final velocity = 30m/s

We have to find work done$.$

★ As per Work-Energy theorem, work done is measured as the change of kinetic energy of moving object.

• W = ∆K

Kinetic energy of body of mass m moving at a speed of v is given by

• K = 1/2 × mv²

Therefore, we can say that

• W = 1/2 × m(v² - u²)

m denotes mass

v denotes final velocity

u denotes initial velocity

W denotes work done

Calculation :

⭆ W = 1/2 × m(v² - u²)

⭆ W = 1/2 × 5(30² - 10²)

⭆ W = 1/2 × 5(800)

⭆ W = 4000/2

⭆ W = 2000J = 2kJ

Cheers!