Question

A certain forces changes the velocity of an object 5m/s to 2m/s in 3sec . Calculate the force applied of it mass is 400kg ?
​

Answer 1

Answer:

Given,

Mass.m = 20 kg.

Initial velocity, u=5m/s

Final velocity, v=2m/s

Work done = change in K.E.

W=

2

1

.mv

2

−

2

1

mv

2

=

2

1

m(v

2

−u

2

)

=

2

1

.20(2

2

−5

2

)

=

2

1

.20(4−25)

=−10.(21)

=−210J

∴ Here, the negative sign implies the retarding

nature of the applied force.

Answer 2

Answer:

Question:-

• A certain forces changes the velocity of an object 5m/s to 2m/s in 3sec . Calculate the force applied of it mass is 400kg ?

Solution:-

• We have to find Force

Given:

• Final Velocity(v) →2m/s
• Initial Velocity (u)→5m/s
• Time→3sec
• Mass→400kg

As we know:

Force=m×a (Where m=mass and a=acceleration)

Acceleration of a body is given by:-

$➝ \frac{v - u}{t}$

By putting the values we get:

$➝a = \frac{(2 - 5)m {s}^{ - 1} }{3}$

$➝a = - 1m {s}^{ - 2}$

Hence we get acceleration= -1m/s²

Therefore force applied:-

➝ F=m×a

➝F= -(400×1)N

➝F=-400N (Answer)

Hence the force applied is -400N.

Hope it helps you ✔️✔️✔️