What is the total mass of a roller coaster if the length of the entire rollercoaster train is 19.5 m the lead car is 3.4 m long
the other 5 cars are 2.7 m long
the mass of each car is 1040 kg
each car can hold up to six passengers
Assume each person has a mass of 50 kg

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.