During a family car trip, a family travels for 1 hour at 70 miles per hour. Then the family travels for 2 more hours at 55 miles per hour. What is the family's average speed during the trip? A. 58.5 mph
B. 65 mph
C. 62.5 mph
D. 60 mph

Argon is adiabatically compressed from an initial volume of 16 liters to a final volume of 2 liters. by what factor do the following quantities change? do they increase or decrease? (a) the rms speed (b) the thermal energy of the gas (c) the molar specific heat cv (d) the pressure

Why should seat belts not be mandatory quick plz

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