Identify two ways of changing the strength of an electric force

Asmall 21 kilogram canoe is floating downriver at a speed of 1 m/s. what is the canoe's kinetic energy?

Mutt and jeff are running along a path each pushing a cart loaded with rocks. if mutt's wagon has a mass two times greater than jeff's and they want to stay together, arriving at their destination at the same time, what must happen? a) jeff should slow down so mutt can catch up. b) mutt must use half as much force to push his cart. c) mutt must use twice as much force to push his cart. d) mutt and jeff will use the same force, but mutt will take bigger steps.

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.