Ok so if each side is 4.53 cm, we can multiply 4.53 x 4.53 x 4.53 to get the volume (since v= l x w x h). Density equals mass/volume, so
519 g/4.53 cm
114.57 g/cm^3 (since none of the units cancel)
As we know the formula of kinetic energy is
here given that
KE = 150,000 J
mass = 120 kg
we can use this to find speed
So speed of above object is 50 m/s
Set up the problem with the conversion rates as fractions where when you multiply the units cancel out leaving the desired units behind.
What are you trying to here?