As a person ages, his or her levels of cardiorespiratory fitness tend to . A. improve B. decline C. stay the same D. none of the above Please select the best answer from the choices provided. A B C D

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.

What is the magnitude of the gravitational force acting on the earth due to the sun?

Why does a collision with an airbag cause less damage than a collision with a steering wheel