An object of mass, m, is suspended from the ceiling by a long string.
An object of mass, m, is suspended from the ceiling by a long string. |
|
|
The object is displaced by an arc such that it is now 10 cm higher than it was originally, and it is released. Calculate the velocity of the object as it passes through its original position. (Take g = 10 m.s-2). |
Solution: When the object is 10 cm above its original position, it has a potential energy Ep = mgh.
When it passes through its original position, all its potential energy is converted to kinetic energy, ½mv2:
So, Ek = Ep
½mv2 = mgh
v2 = 2gh = 2 x 10 x 0.1 = 2
v = √2 = 1.41 m.s-1
