Question

if mass of an object is increased by 4 times and velocity is halved, the kinetic energy will be:?

Answer 1

we know,

Mass = m

Velocity = v

Kinetic energy = 1/2mv^2

Here,

Mass = 4m

Velocity = 1/2v

Kinetic energy = 1/2mv^2

=>1/2 × 4m × (1/2)^2v

=> 1/2 mv^2

So, the kinetic energy remains the same

Cheers!

Answer 2

Kinetic energy of an object is given by

½mv²

Here,

m - mass

v - velocity

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According to the question,

The new mass is four times the original one.

New Mass = 4m

New velocity is halved.

New velocity = $\frac{v}{2}$

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Substituting the new mass and velocity in the formula, we get.

${K_{e}}$ = ½ × 4m × $\frac{v^{2}}{4}$

${K_{e}}$ = ½mv²

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Thus, the kinetic energy remains the same.