What of the following is a true statement regarding springs? a. in hooke's law, the force exerted by the spring acts in the same direction as displacement. b. springs are designed to provide unpredictable variations in force. c. the force exerted by a spring has a quadratic relationship with the displacement from equilibrium. d. the higher the value of the spring constant, the stiffer the spring. e. the spring constant is represented by the symbol cs

mistakes are ok

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.