It is claimed that if a lead bullet goes fast enough, it can melt completely when it comes to a halt suddenly, and all its kinetic energy is converted into heat via friction. find the minimum speed of a lead bullet (initial temperature = 39.0

 v = 271.6 m/s

Explanation:

In this problem the lead bullet has a kinetic energy given by

    K₀ = ½ m v²

All this energy is transformed into heat when the bullet stops (vf = 0)

The equation for the heat of a body is

    Q = m ΔT

Where we must take the specific heat of lead (ce = 128 J / kg mol and the melting temperature 327.3º

that the transformation is complete

    K = Q