How are loudness and intensity related to the amplitude and energy of a sound wave? what is the unit of intensity?

What is a subatomic particle with a negative charge and very little mass?

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.

Emagnitude of the electrical force acting between a +2.4 ×  10–8  c charge and a +1.8 ×  10–6  c charge that are separated by 0.008 m is    n, rounded to the tenths place.