Recall that in the equilibrium position, the upward force of the spring balances the force of gravity on the weight. use this concept to estimate the spring constant k of spring #1

In positive numbers less than 1, the zeros between the decimal point and non zero are significant

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation