Question

A bullet of mass m= 10 gram strikes a ballistic pendulum of mass m=2.0 kg. the center of mass of the pendulum rises a vertical distance of h=12 cm. assuming the bullet remains embedded in the pendulum, calculate its initial speed.

Answer 1

Assumption made: No energy is loss!
The g is 10N/kg
Total mass = 0.01kg+2kg= 2.01kg
Gravitational Potential Energy= 2.01kg * 0.12m * 10N/kg = 2.412J
Kinetic energy = 2.412J since no energy is lost
Velocity =( (2.412J * 2 )/ 2.01kg )^0.5= 1.55m/s