Question

A 8kg cat is running 4m/s. how much kinetic energy does it have?

Answer 1

The formula for kinetic energy is, ${ E }_{ k }=\frac { 1 }{ 2 } \cdot m\cdot { v }^{ 2 }$ 
where m is mass and v is velocity.

Let's plug the given values in the formula.

${ E }_{ k }=\frac { 1 }{ 2 } \cdot m\cdot { v }^{ 2 }\\ \\ { E }_{ k }=\frac { 1 }{ 2 } \cdot 8\cdot { 4 }^{ 2 }\\ \\ { E }_{ k }=\frac { 1 }{ 2 } \cdot 8\cdot 16\\ \\ { E }_{ k }=4\cdot 16\\ \\ { E }_{ k }=64\quad$

It's kinetic energy is 64 Joules.

Answer 2

Kinetic energy = (1/2) (mass) (speed)²

Kinetic energy = (1/2) (8 kg) (4 m/s)² =
 
                                  (4 kg) (16 m²/s²) =

                                   64  (kg-m/s²) (m) = 64 newton-m = 64 joules


And may I say . . . that is one fat cat !     (about 17.6 pounds)