Harry and hagrid needed to get money out of gringotts bank. the bank cart was accelerating at a rate of 4 m/s2 and it had a mass of 8,000 kg. what is the net force acting on the cart? use the formula: f=m∙a show all your work!

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?

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f

What effects result when there is an impact between earth and an asteroid? check all that apply. a.massive flooding. b.extinction of many life forms.c.major earthquakes change in average global temperature.d. giant dust cloud