What speed do raindrops fall at????????????????

Question

im sure it is affected by wind speed/direction...... but a rough idea anyone?????????

Answer 1

A number of people have quoted 32 feet/s or 9 m/s, referring to acceleration due to gravity. Acceleration measures change in speed and is measured in units of feet per second per second or meters per second per second. So this is not the same as the 'speed' at which the raindrops fall.

Neglecting effects due to wind, the raindrop will have two main forces acting on it - downward force due to gravity, upward force due to air resistance (or drag). Buoyancy can be neglected given that water is considerably more dense than air.

Air resistance increases with speed (proportional to square of velocity) so initially the rain drop will accelerate downward at something less that 'g' (acceleration due to gravity - 9.8 m/s/s).

As drag increases, the acceleration downward will decrease due to the opposing upward force of drag until a speed is reached at which the downward force of gravity is balanced by the upward drag.

Once the forces are balanced (and neglecting other effects like I said) there will be no more change in velocity - that's one of Newtons Laws of motion. The speed at which the rain drop is now moving downward is called terminal velocity.

Acceleration due to gravity is constant and independent of mass. As well as changing with velocity, drag depends on cross sectional area and a number of other properties. So larger drop will experience more drag and fall slower.

According to the wonderquest web site the range of terminal velocity for raindrops is roughly 2 m/s to 9 m/s (5 to 20 mph)

Hope that helps.

Answer 2

Large raindrops fall at up to 30 feet per second (20 m.p.h.), and an average size raindrop falls about 21 feet per second (14 m.p.h.). When the wind blows, it does affect the drop, it directs it to a angle, not straight down, so the stronger the wind, the more angle the drop will have.

Answer 3

They fall at the speed at which air resistance exactly balances their weight. This speed depends on the size of the drops - small droplets as in a fine drizzle fall more slowly than big splashy drops.
Their speed is much less than the speed you would fall at (i.e. your terminal velocity). Presumably therefore free-fall skydivers have raindrops apparently hitting them from below!

Answer 4

terminal velocity for raindrops depends on at what altitude the raindrop is. The terminal velocity is approximately 7 m/s which is about 25 km/hour. 15 mph

Answer 5

That's a good question.

I am sure it depends on the size of raindrops, but from casual observation it is around 20 miles per hour.

Answer 6

32 feet per second ^2 - until they reach terminal velocity. But that is variable depending on conditions. Consider that sometimes they blow sideways, or are caught in currents and raised high enough to freeze into hail. I'd guess it would average well under 100 mph, but you'd only be able to guess unless you were measuring a particular drop under specific conditions.

Answer 7

It will fall at differing speeds depending on the size and weight of the rain drop.

Answer 8

draw a image start up with a right this moment horizontal line, this line represents the fee of the automobile with appreciate to the earth, that's 55km/h. next from that tip of the line draw a line right this moment down, this represents the fee of the raindrops with appreciate to the earth. Now, you have 2 strains, draw yet another line connect them to variety a triangle. The final line is the fee of the rain with appreciate to the automobile, and it varieties a 20degree perspective with the 55km/h line. cos20 = fifty 5 / Vrc Vrc = fifty 8.fifty 3 km/h

Answer 9

Raindrops falls at 9.8 meters per second (m/s) or 32 feet per second (ft/s) due to the gravity constant.

Answer 10

DoctorBob's answer seems to be the most accurate.
It might be worth noting that the most streamlined shape in nature is a raindrop.