Answer:
v = 0.54 m/s
Explanation:
The Principle Of Conservation Of Mechanical Energy
In the absence of friction, the total mechanical energy is conserved. That means that
Em=U+K is constant, being U the potential energy and K the kinetic energy
U=mgh
[tex]\displaystyle K=\frac{mv^2}{2}[/tex]
When the mass (m=1 kg) of the pendulum is at the top of the path at a height of h=1.5 cm=0.015 m, its kinetic energy is 0 and its potential energy is:
U=1 * 9.8 * 0.015 = 0.147 J
That potential energy is completely transformed into kinetic energy at the bottom of the swing. The speed can be calculated by solving for v:
[tex]\displaystyle \frac{mv^2}{2}=0.147[/tex]
Multiplying by 2 and dividing by m:
[tex]\displaystyle v^2=\frac{2K}{m}[/tex]
[tex]\displaystyle v^2=\frac{2*0.147}{1}=0.294[/tex]
[tex]v=\sqrt{0.294}[/tex]
v = 0.54 m/s
