We want to construct a thermometer using mercuyr. as the mercury in the bulb is heated, it expands and moves up the thin capillary tube connected to the bulb. the symbol used for the coefficient of of volume expansion of a substance due to ta temperature increase is b(sigma). it is used in the following equation: deltav = bv(deltat)

second mirror gathers light from a faraway object and reflects it to another mirror. - a.

hi there!

out of the two, (b) precision would be more reasonable.   however, both a and b could be pretty reasonable.

-awesomerepublic   : )

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.

a skateboard rolling across the street - apex