Question

A 0.07-kg lead bullet traveling 257 m/s strikes an armor plate and comes to a stop. If all of the bullet's energy is converted to heat that it alone absorbs, what is its temperature change?

Answer 1

Answer:

ΔT = 258°C

Explanation:

mass of bullet, m = 0.07 kg

velocity of bullet, v = 257 m/s

According to the energy conservation law, the kinetic energy of bullet is totally converted into form of heat energy.

let ΔT be the rise in temperature of the bullet, c be the specific heat of lead.

c = 0.128 J / g°C = 128 J/kg°C

$\frac{1}{2}mv^{2}=mc\Delta T$

By substituting the values

0.5 x 0.07 x 257 x 257 = 0.07 x 128 x ΔT

ΔT = 258°C