A piece of lead falls from a height of 100 m on a fixed non - conducting slab which brings it to rest . The temperature of the piece immediately after collision increase by ( specific heat of lead is `30.6 cal kg^(-10) C^(-1) `and` g= 9.8ms^(-2)`)

Options

A. 0 K
B. `27^(@)C`
C. `7.63^(@)C`
D. 4.2 K

Answer

C

Explanation

Heat produced = Potential energy of the piece.
` msDelta t = (mgh)/(j) `
`implies (30.6) Delta t = ((9.8) (100))/(4.2)`
`therefore Delta t = 7.625 ^(@)C`