Kinetic energy KE of a body of mass m moving with velocity or speed v is given by the formula:

KE₁ = mv₁²

If the speed of particle is doubled then

KE₂ = mv₂² where, v₂ =v₁

Substituting the value of v₂ in the formula,

KE₂ = m (2v₁)²

= (4 mv₁²)

KE₂ = 4 KE₁

So kinetic energy will become 4 times if the speed is doubled.

On other hand, acceleration depends on final as well as initial velocity, and here acceleration will be same.

Weight is independent of change in speed.