Three runners compete in a 400m race on an oval-shaped running track. At a certain time, one runner is 15m away from the finish line. Which term describes the finish line?

Reference point.

Explanation:

Motion can be defined as a change in location (position) with respect to a reference point.

This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.

In this scenario, three runners compete in a 400m race on an oval-shaped running track. At a certain time, one runner is 15m away from the finish line. Thus, the term which best describes the finish line is a reference point.

A reference point can be defined as a fixed point that typically marks the position from which a body starts its motion or change its location.

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

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.