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ritwik06
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Homework Statement
A bullet of mass 50 g is fired from below into the bob of mass 450 g of a long simple pendulum. The bullet remains inside the bob and the bob rises through a height of 1.8 m. Find the speed of the bullet. Take g=10
Homework Equations
Momentum remains conserved
Energy remains conserved
The Attempt at a Solution
I tried to solve this using two methods and thereby I got two differnt answers. Tell me where am I wrong.
Using Kinematics:
Let th speed of the bullet be v. Let the velocity after th bullet is embeed is V. by the principle of conservation of linear momnetum:
[tex]V=\frac{(0.05 Kg)v}{0.45+0.05}=\frac{v}{10}[/tex]
Using v^2=u^2+2ax
v=60 m/s
2nd method:
Momentum remains conserved
Energy remains conserved
Kinetic energy of the bullet =change in potential energy of the bullet bob system.
0.5*0.05*v^2=0.5*10*1.8
[tex]v=\sqrt{360}[/tex]