Amass of 30.0 grams hangs at rest from the lower end of a long vertical spring. you add different amounts of additional mass δm to the end of the spring and measure the increase in length δl of the spring due to the additional mass. you plot your data in the form δl (vertical axis) versus δm (horizontal axis). plotted this way, your data lies very close to a straight line that has slope 0.0268 m/kg. what is the force constant k of the spring? use g = 9.80 m/s2.

366N/m

Explanation:

According to Hooke's law:

avoiding the minus symbol and substituting the force to the gravitational force, we have:

The spring constant is 366N/m

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.