To do this we will be equating two types of energies. The first is potential energy which is associated with the energy of the object at a specific height. We will assume all of the energy will be converted to kinetic energy which is energy associated with the objects motion.
Potential Energy = Energy associated with an object at a specific height = mgh = mass * gravity * height
Kinetic Energy = 0.5mv^2 =0.5mvv= 0.5*mass*velocity^2
The “^” symbol is the exponential symbol in shorthand.
Note:
Potential Energy will be converted to Kinetic Energy so:
mgh = 0.5mv^2
See how mass is on both sides? This means that it does not matter the mass of the object in terms of how fast this object will get going. Final velocity will not be a function of mass.
Let’s divide both sides by m.
gh = 0.5v^2
Now, let’s calculate velocity.
gh/0.5 = 2gh =v^2
Now let’s square root both sides to remove the squared exponent.
sqrt(2gh) = velocity.
Now you know how to calculate the speed of an object if you let it go from a specific height.
Here is a calculator to do this online:
http://www.bishopkingdom.com/aichatbox/equations/101/
Other calculators similar to this can be found here.