Q. 65.0( 2 Votes )

# A 1 kg mass has a kinetic energy of 1 joule when its speed is:

A. 0.45 m s^{–1}

B. 1 m s^{–1}

C. 1.4 m s^{–1}

D. 4.4 m s^{–1}

Answer :

Given,

Mass of body m= 1 kg

Kinetic energy = 1 J

Velocity v=?

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

Substituting the given values in the equation:

1 J = *×1× v ^{2}*

*1×2 = v ^{2}*

*v ^{2} = 2*

*v=*

v= 1.4 ms^{-1}

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