Fossil fuels currently account for the majority of the world’s energy use because they are a. renewable energy resources. b. distributed evenly throughout the world. c. relatively inexpensive and readily available. d. nonpolluting.

Which component of the earth’s atmosphere is decreased due to photosynthesis?

Which of the following is not an appropriate unit for acceleration? (kg/12 mihr? m/min/sec cm/30c?

Estimate the kinetic energy of mars with respect to the sun as the sum of two terms, that due to its daily rotation about its axis, and that due to its yearly revolution about the sun. (assume mars is a uniform sphere with mass = 6.4×10 to the power of 23 kg, radius = 3.4×10 to the power of 6 m, rotation period = 24.7 hours, orbital period = 686 days and is 2.3×10 to the power of 8 km from the sun.)