Question

9
Q25 Long ans type question
1
(a) Sate newtons' Law of motion?
Drive it's mathematical
Expression?
(b) A constant force acts on an
object of mass 5 kg for duration of
2 sec. It increases its velocity of 3
m/sec to 7 m/ sec. Find the force
acted on the object?​

Answer 1

1) a) Newton's first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. ... The third law states that for every action (force) in nature there is an equal and opposite reaction.

In equation form, Newton's second law of motion is a=Fnetm a = F net m .

b). Given,

mass=5kg

t

1

=2s

Initial velocity u=3m/s

Final velocity v=7m/s

t

2

=5s

So,

Let the Force be F

Let the acceleration be a

So,

a=

t

(v−u)

=

2

(7−3)

=2m/s

2

So the magnitude of the applied force is 10N

And the final velocity after 5s is v

So,

v=u+at

v=3+2×5

v=13m/s

The final velocity after 5s is 13m/s