The energy flux from the sun has a peak value of around 1500 W/m2, and solar cells are around 15% efficient. Estimate the area needed to satisfy US energy needs using solar cells, using the estimates that there are about 350 million people in the US and that we use an average of 90 kW/person. Also assume that there are about 6 hours of "peak" sunlight per day. Answer in square kilometers

The long handle on a rake is a(n) a. lever b. screw c. wedge d. inclined plane

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?

Marcella is a four-year-old girl who is a victim of emotional child abuse. based on the child and family services improvement and innovation act of 2011, which action should the government take for marcella? a. the state should arrest marcella’s abuser. b. the state should find a home for marcella as soon as possible. c. the state should enforce stricter laws in the area where marcella resides. d. the state should provide medical assistance to marcella.