Which statement about force is incorrect A. Some forces cause objects around us to move.
B. Some forces keep objects around us from moving
C. Force is the ability to change motion and transfer matter.
D. Force causes changes in the motion and energy of matter.

What color would an object that reflects green and blue light appear to be in white light? a. blue b. cyan c. magenta d. black

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.

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)