Question

Suppose kinetic energy is 4 joules of a moving object what will happen if we increase the speed twice

Answer 1

Answer:

The kinetic energy is 16 joules.                        

Explanation:

Kinetic energy (E) is given by:

$E = \frac{1}{2}mv^{2}$

Where:

m: is the mass

v: is the speed

When the kinetic energy is 4 joules, the speed of the object is:

$v_{1}^{2} = \frac{2E_{1}}{m} = \frac{8}{m}$                         

Now, if the speed is increased twice then we have:

$E_{2} = \frac{1}{2}mv_{2}^{2} = \frac{1}{2}m(2v_{1})^{2} = \frac{1}{2}m[4(\frac{8}{m})] = 16 J$

Therefore, the kinetic energy is 4 times the initial value.  

I hope it helps you!