A certain object has 11 J of kinetic energy while traveling at 22m/s. At what speed does it need to travel to have 15 J of kinetic energy?

25.8m/s

Explanation:

KE = 1/2 mv^2.

KE = 11J, Velocity = 22m/s, mass =m

We don't have mass since it's unknown so we calculate for mass and use that to find the second part of the question.

So KE = 1/2mv^2

11J = 1/2 x m x (22)^2

11 = 1/2 x m x 484

11 = 242m

11/242 =m

M =0.045kg

So we solve the second part and find velocity if KE is 15J with mass 0.045kg

KE =1/2 mv^2

15J = 1/2 x 0.045kg x v^2

15J = 0.0225 x V^2

15J/0.0225kg = V^2

666.6 = V ^2

V= sqr root of 666.6

V = 25.8m/s

b. a lightning bug, plug of grass, and a worm