Answer:
The kinetic energy is 16 joules.
Explanation:
Kinetic energy (E) is given by:
[tex] E = \frac{1}{2}mv^{2} [/tex]
Where:
m: is the mass
v: is the speed
When the kinetic energy is 4 joules, the speed of the object is:
[tex] v_{1}^{2} = \frac{2E_{1}}{m} = \frac{8}{m} [/tex]
Now, if the speed is increased twice then we have:
[tex] E_{2} = \frac{1}{2}mv_{2}^{2} = \frac{1}{2}m(2v_{1})^{2} = \frac{1}{2}m[4(\frac{8}{m})] = 16 J [/tex]
Therefore, the kinetic energy is 4 times the initial value.
I hope it helps you!