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If an object with a mass of #2 kg # changes speed from #6 m/s# to #2 m/s#, by how much does its kinetic energy change?

Answer 1

Layla Ahmed

So the kinetic energy was reduced by a factor of #4#. Or, equivalently, the kinetic energy was reduced by #27 "J"#.

Prior to:

#E_k = 1/2mv_i^2 = 1/2(2)(6)^2 = 36 " J"#

Following:

#E_k = 1/2mv_f^2 = 1/2(2)(3)^2 = 9 " J"#

So the kinetic energy was reduced by a factor of #4#. Or, equivalently, the kinetic energy was reduced by #27 "J"#.

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Answer 2

Amelia Adams

The kinetic energy change of the object is 16 Joules.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.