If 80mg of a radioactive element decays to 10 mg in 30 mins., what is the element's half-life in minutes? a- 10  b- 20  c- 30  d- 40

The graph above shows how the price of cell phones varies with the demand quantity. the equilibrium price for cell phones is where both supply and demand quantities equal $100, 5,000 5,000, $100

The blackbody curve for a star name zeta is shown below. what is the peak wavelength for this star ?

Mike and mitchell decide to have a foot race. they mark off a stretch of 100 yards, and recruit cindy to work the stopwatch. after running the race and looking at the results, cindy declared that mitchell was the fastest. so how did the boys times compare?