Alead bullet at 27°c just melts when stopped by an obstacle. assuming that 25 % of heat is absorbed by the obstacle, find the velocity of the bullet if its initial temperature is 27^{\circ}c. [for lead, melting point = 327^{\circ}c, specific heat = 0.03 cal/g-^{\circ}c, latent heat of fusion = 6 cal/g and j = 4.2 j/cal.]

409.87803 m/s

Explanation:

v = Velocity of bullet

L = Latent heat of fusion = 6 cal/g

c = Specific heat of lead = 0.03 cal/g°C

= Change in temperature = (327-27)

m = Mass of bullet

The heat will be given by the kinetic energy of the bullet

According to the question

This heat will balance the heat going into the obstacle

The speed of the bullet is 409.87803 m/s