Which object has the greatest inertia?

(1) a 0.010-kg bullet traveling at 90. m/s

(2) a 30.-kg child traveling at 10. m/s on her bike

(3) a 490-kg elephant walking with a speed of

1.0 m/s

(4) a 1500-kg car at rest in a parking lot

I believe 4

but im really not sure

The greatest amount of inertia can be calculated by the following equation

Kinetic Energy = 0.5 x mass x (velocity) ^2

You are trying to find Kinetic Energy.

KE = 0.5 x 30kg x 100

KE = 1,500

Your answer is (2) because when using the equation, the child has the greatest amount of inertia.