b) A human can generate power of about 80 W. If one person works to raise water for 4 hours every day, what is the approximate volume of water that can be pumped from a 5 meter deep well in a month, assuming 50% efficiency? c) The water is to be used to irrigate a field of wheat, which requires a total of 15 cm depth of water over a three-month growing season. Using the answer from (b), how much area can be irrigated to a depth of 5 cm each month? d) If the yield of wheat is 0.1 kg/m², and the energy equivalent of wheat is 7.5 MJ/kg, what is the total energy produced by the field of wheat over a season?

If the average household in a region consumes about 5,250 kWh of energy per year. In the region, the average annual solar energy potential is about 1,450 kWh/m² per year. If solar panels are available in sizes of 1 m x 1 m with an efficiency of 18 %, how many panels will be needed to power a house? (Since you can't have a fraction of panel, always round up you number to the next integer.) Your Answer: Answer

Consider a water reservior. The resrvoir graduallly loses water, because people insist on showering, washing clothes, etc.  The "use rate" R is the rate at which consumers use the water.   On April 13, between 1pm and 2pm, R is 5-gallons per second. How much water was drained from the reservoir between 1pm and 130pm?  At midnight, when everyone was asleep, a big industrial water user suddenly becomes active. Let A denote the amount of water taken from the reservoir (in gallons),  with A = 0 at midnight. It turns out that A=2t2 with t expressed in seconds. Given this information, calculate R, the use rate, at t = 10 s.

Suppose that 6 J of work is needed to stretch a spring from its natural length of 28 cm to a length of 34 cm. (a) How much work is needed to stretch the spring from 30 cm to 32 cm? (Round your answer to two decimal places.) (b) How far beyond its natural length will a force of 30 N keep the spring stretched? (Round your answer one decimal place.) cm

A hot tub with a surface area of 28 ft2 is filled with water to a depth of 29 in . Hint: volume is calculated as area × height (A × h). A) What is the volume of water in the tub, in liters? Express your answer to two significant figures and include the appropriate units. B) How many kilojoules are needed to heat the water from 59∘F to 103 ∘F? Express your answer to two significant figures and include the appropriate units. C) If the hot-tub heater provides 5900 kJ/min, how long, in hours, will it take to heat the water in the hot tub from 59∘F to 103∘F? Express your answer to two significant figures and include the appropriate units.

The figure below is that of an object being pushed up an incline. The object has mass of m - 4.9 kg and it is pushed up the incline with a force of F= 26.0 N to the top at a constant speed. The incline is 12-meters long and h 3.1 meters high. Based on this information, please determine the efficiency for this inclined plane to three decimal places. Enter your answer as a decimal, not a percentage (0.224 and not 22.4%) Your Answer: 12.0 m F E

In an attempt to find the food calories provided by various fruits, you collect the following information, which is given in various units: pineapples have 125 Calories of energy, mangos have 271,960 joules of energy, and grapes have 87,000 calories of energy. Select the option that correctly ranks the fruits from greatest to least energy supplied.