Write the expression for kinetic energy with help of Newton's law of motion
Answers
Answer:
Energy possed by a body by virtue of its motion is referred to as Kinetic Energy.
Consider a body of mass 'm' starts moving from rest. After a time interval 't' its velocity becomes V.
If initial velocity of the body is V
i
=0, final velocity V
f
=V and the displacement of body is 'd'. Then, first of all we will find the acceleration of body.
Using equation of motion 2aS=V
f
2
−V
i
2
Putting the above mentioned values we get, 2ad=V
2
−0.
That is, a=
2d
V
2
.
Now force is given by, F=ma .
Putting the value of acceleration, we get,
F=m(
2d
V
2
).
As we know that Work done =Fd.
Putting the value of F, we get, Workdone=(
2d
mV
2
)(d)=(
2
mV
2
)=
2
1
mv
2
.
Therefore, the expression for kinetic energy is
2
1
mv
2
Answer:
Work Done, W= Force * distance
W= F*s ............................(1)
Using Newton's law of motion, v² - u² = 2as
s = v² / 2a ........(3) (initial velocity,u=0)
F = ma .............(2)
using (2) in (1)
W = ma * s
W = ma * v² / 2a .................using (3)
W = Kinetic Energy = 1/2 mv²