An object releasing energy is evidence of which type of chemical change?

Achild has maximum walking speed of 1.6 m/s. what is the length of the child's legs? 0.26 m

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.

Given the data calculated in parts a, b, c, and d, determine the initial rate for a reaction that starts with 0.85 m of reagent a and 0.70 m of reagents b and c?