Minecraft – the terminal velocity of a sheep

minecraft-java-edition

I am thinking of an alternative timing mechanism; I am building a trap and I wanted to try something different to set it off.

I want to drop a sheep from n blocks high so that I have a delay before the trap is triggered. The timing needs to be very exact, but I don't know how the falling mechanism works: whether there is acceleration, and how fast it is hit. (I understand this would be different for a chicken.)

Can someone give me some figures of the length of time it takes to reach the terminal velocity, and how many blocks per second a mob will fall at terminal velocity?

50 bonus points for the answer for chicken speeds as an extra: This will be applied after two days; the best answer in reference to chickens will get the bounty.

What do you mean, an African or European sheep? Alex

It is an Unladen European Sheep.

Now a Post on Physics SE

The winner is confirmed as he was the sole entry but thanks for all the comments which made the answer so brilliant, as soon as the system lets me i will be giving Caleb +100 bounty

Best Answer

Falling speed is explained in the "Transportation" page on the wiki:

Every tick (1/20 second), non-flying players and mobs have their vertical speed decremented (less upward motion, more downward motion) by 0.08 blocks per tick (1.6 m/s), then multiplied by 0.98. This would produce a terminal velocity of 3.92 blocks per tick, or 78.4 m/s.

Terminal Velocity

As stated above, terminal velocity in Minecraft is 78.4 m/s, but this speed cannot be reached in survival mode:

However, the sky isn't quite high enough for that: Falling from layer 256 to bedrock takes about 5.5 seconds, with impact at 3.5 blocks per tick (70 m/s).

In creative mode, you can fly higher, and could potentially reach terminal velocity falling from "above the sky".

Acceleration

Acceleration is not talked about on the wiki, however see the change in velocity over time in the following graph. The graph was created using the formula:

v(t) = (0.98^t - 1) × 3.92

graph showing the change in velocity over time

You will notice that acceleration is not constant, and decreases over time.

How Long?

Using the velocity time graph, we can find how long it would take to reach terminal velocity.

10% Terminal Velocity (0.392 blocks/tick) : ≈ 5 ticks (0.4 seconds)

50% Terminal Velocity (1.96 blocks/tick) : ≈ 35 ticks (1.75 seconds)

75% Terminal Velocity (2.94 blocks/tick) : ≈ 69 ticks (3.45 seconds)

99% Terminal Velocity (3.8808 blocks/tick) : ≈ 228 ticks (11.4 seconds)

100% Terminal Velocity (3.92 blocks/tick) : ≈ 672 ticks (33.6 seconds)

Chicken Science!

I couldn't find anything on the falling speed of chickens, so I set my own apparatus to test. It involves a 10 block fall with a pressure plate at the bottom, turning on a redstone lamp. I start the timer at the same time that I press the button, and stop the timer when I see the lamp turn on:

My chicken-speed mechanism