Question

One student doubts the expression for K.E as K.E = mv³ or KE
=½mv².
How can you help
him.​

Answer 1

Answer:

The expression for Kinetic energy (K.E.) is given by

K.E.=1/2 mv²

Explanation:

Kinetic energy is the energy possessed by a particle due to its motion.

Derivation:

Let an object of Mass M is moving with a velocity of v m/s.

Let an object of Mass M is moving with a velocity of v m/s.The work done to stop the object is called the Kinetic energy of the Object.

W=F.s

where F=force required to Stop the object

where F=force required to Stop the objects= displacement by the object

we know that F=m.a

where, m = mass and a= acceleration

putting this in the Work formula we get

W= m.a.s.

From the 3rd law of motion ,We also have

v²=u²+2as

v²=u²+2ass=1/2a(v²-u²)

v²=u²+2ass=1/2a(v²-u²)at rest, u=0, so it becomes

v²=u²+2ass=1/2a(v²-u²)at rest, u=0, so it becomess=(1/2a)v²

putting the value of s in the above equation, we get,

W=m×a×(1/2a)v²

W=m×a×(1/2a)v²W=1/2mv²

This can be written as K.E=1/2 mv²

Answer 2

Answer:

The correct expression for kinetic energy is K.E = 1/2 mv^2.

Explanation:

• The energy an object has as a result of motion is known as kinetic energy in physics.
• It is described as the effort required to move a mass-determined body from rest to the indicated velocity.
• The body keeps the kinetic energy it acquired throughout its acceleration unless its speed changes.
• Mechanical energy, also known as kinetic energy or potential energy, is the energy that an object possesses when it is in motion or the energy that an object stores due to its location.
• Renewable energy is also fueled by mechanical energy.
• In order to efficiently produce electricity or convert energy, many sources of renewable energy depend on mechanical energy.

KE = 1/2mv^2 is the correct expression for kinetic energy.

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