Q. 233.7( 3 Votes )

# A block of mass 5 Kg is lying on a frictionless table. A force of 20 N is applied on it for 10 seconds. Calculate its kinetic energy.

Answer :

Given,

Mass of body = 5 kg

Force F = 20 N

Time t = 10 seconds

To find: kinetic energy??

Initial velocity u = 0

Let final velocity be v

We know,

So, acceleration = 4 ms^{-2}

We also know that,

Substituting value of acceleration and u in this formula:

v = 10 s × 4 ms^{-2}

v = 40 ms^{-1}

Kinetic energy *=* *m v ^{2}*

*Substituting value of v in the equation*

*Kinetic energy =*

*= 4000 J*

*= 4 KJ*

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