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Derive the expression for kinetic energy of an object having mass m.

a) KE = 1/2mv^2
b) KE = mv
c) KE = m^2v^2
d) KE = mv^2/2

User Mag Roader
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1 Answer

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Final answer:

The expression for kinetic energy is KE = 1/2mv², which indicates kinetic energy is proportional to the mass of the object and the square of its velocity. The incorrect formula KE = mv² lacks the division by 2, which is essential for the correct expression.

Step-by-step explanation:

The expression for the kinetic energy (KE) of an object with mass m moving at velocity v is derived from the work-energy principle. It states that the work done on an object is equal to the change in its kinetic energy. The correct formula for kinetic energy is KE = 1/2mv².

When an object with mass m is accelerated to a velocity v, the work done to accelerate the object is stored as kinetic energy. Since this energy is associated with the object's movement, any change in its speed results in a change in its kinetic energy. This concept leads us to the expression KE = 1/2mv², signifying that kinetic energy is proportional to the mass of an object and the square of its velocity.

If we were to consider the incorrect expression KE = (m)(v)² for kinetic energy, we would find that it lacks the correct factor of 1/2, making option c the correct critique of this formula.

User Avinash Raut
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