Question

If the speed of a particle is decreased by a factor of three, by what factor does its kinetic energy change?

Answer 1

decreases by 1/9

Step-by-step explanation:

the equation of kinetic energy is
`KE = (mv^2)/(2)\\`

here, we see that Kinetic Energy and v (velocity) are on opposide sides of the equation, this means that they are directly proportional (when one increases, the other one must increase (assuming mass (m) is constant)): KE∝
`v^2`

since V is decreasing by factor of 1/3, simply plug it in for v^2 to get (1/3)^2,

this equals (1/9). So KE will become 1/9 of original value