Which of the following statements about geothermal energy is not true?
a. it is not a practical source of energy.
b. it is an important source of energy in volcanically active areas.
c. it works best when the magma pool is near the surface of earth.
d. it is a renewable source of energy.

Air is held within a frictionless piston-cylinder container, which is oriented vertically. the mass of the piston is 0.45 kg and the cross-sectional area is 0.0030 m2. initially (state 1) the pressure of the gas is sufficient to support the weight of the piston as well as the force exerted by the atmospheric pressure ( 101.32 kpa). the volume occupied by the air within the cylinder in state 1 is 1.00 liter. one end of a spring (with spring constant k = 1000 n/m) is attached to the top of the piston, while the other end of the spring is attached to a stage that can move vertically. initially the spring is undeflected and therefore exerts no force. then the stage is then moved quasistatically downward a distance of 10.0 cm, at which point the system reaches state 2. the piston-cylinder is not insulated; rather it remains in diathermal contact with the surroundings, which are at a constant temperature of 300 k. what is the change of pressure within the container?

What causes the formation of ocean currents?

Asemipermeable membrane is placed between the following solutions. which solution will decrease in volume? solution a: 1.4% (m/v) starch solution b: 7.62% (m/v) starch