If you throw a ball up with a velocity of 3 m/s, how long will it take for the ball to reach the top of its path? 3.31 sec
2.31 sec
1.31 sec
0.31 sec

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.

Where is the potential energy throughout the loading, cocking, and releasing of the trebuchet?

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?