A study finds that there is a positive correlation between height and math test scores. The researcher concludes that taller people are better at math. However, another researcher points out that height is also correlated with age, and age is correlated with greater knowledge of math. What issue does this example represent?

What is the magnification of a real image if the image is 10.0 cm from a mirror and the object is 50.0 cm from the mirror ? use the equation m=-di/do. a. -5.0 b. 5.0 c. 0.20 d. -0.20

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

Select all of the following that are equal to an impulse of 20 unitsa) force= 5, time= 5.5b) force= 25, time= 0.8c) force= 0.1, time= 200d) force= 10, time= 2(its b, c, and d)(also in order to find answer they have to add to get the unit)ex= 25x.8=20 or .1x200=20