A6.30 kg piece of solid copper metal at an initial temperature t is placed with 2.00 kg of ice that is initially at -16.0 ∘c. the ice is in an insulated container of negligible mass and no heat is exchanged with the surroundings. after thermal equilibrium is reached, there is 0.90 kg of ice and 1.10 kg of liquid water. what was the initial temperature of the piece of copper?

179 degree

Explanation:

Solid copper will lose heat to warm up and melt ice . Since all the ice has not melted so final temperature of mixture will be zero.

heat gained by ice to reach temperature of zero degree

= mass of ice x specific heat of ice x rise of temp  

= 2  x 2093 x 16 = 66976 J

Heat gained to melt 1.1. kg of ice

mass x latent heat of ice

1.1 x 334000

= 367400

total heat

= 367400 + 66976

=434376

Heat lost by copper

= 6.3 x 385 x T

where 385 is specific heat of copper and T is initial temperature

heat lost = heat gained

6.3 x 385 T = 434376

T = 434376 / (6.3 x 385)

= 179 degree .

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.