Question

A lead bullet penetrates into a solid object and melts Assuming that `50%` of its K.E. was used to heat it , calculate the initial speed of the bullet , The initial temp , of bullet is `27^(@)c` and its melting point is `327^(@)C` Latent heat of fasion of lead ` = 2.5 xx 10^(4) J kg^(-1)` and sp heat capacity of lead `= 1.25 J kg^(-1) K^(-1)`

Answer 1

`1/2 (1/2 mv^2) = msDeltatheta + mL`
`:. v=2(sqrt(sDeltatheta)+L)`
`=(sqrt((125)(327-27) + 2.5 xx (10^4)))`
`=500 m//s `