1. A 10 kg rubber block sliding on a concrete floor (μ=0.65) 2. A 248 kg object moving at 19 m/s comes to stop over a distance of 38 m. What is the coefficient of kinetic friction between the surfaces? HURRY 50pts and dont take the points just answer the question

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.

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.

What structural formula represents 4 electrons shared between two atoms?