Question

Consider a moving cart of mass 120 kg
with a kinetic energy K. If its velocity is
doubled, how much should the mass be
decreased so that the KE does not change?​

Answer 1

Explanation:

Kinetic energy =

2

1

mv

2

Where we have taken v as velocity.

If we replace v with 2v, we have:

Kinetic enWhat happens when speed doubles kinetic energy?

Have you planned financially for your retirement?

No. The (non-relativistic) kinetic energy of an object of mass m traveling at velocity v is

Ekin=12mv2

If the velocity is doubled, the kinetic energy is quadrupled, because squaring the factor of 2 gives 4.

Deriving the kinetic energy is easy:

Work W (or energy E ) is defined as force F times distance s :

E=F⋅s

Since for constant acceleration from 0 to v , F=m⋅a , v=a⋅t and s=12⋅a⋅t2 ,

it follows that

E=m⋅a⋅12⋅a⋅t2=12⋅m⋅a2⋅t2=12⋅m⋅v2

⟹4K