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Degorath

Jump time vs Fall time

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Am I right in assuming that: As you must obviously exert more force on an object / yourself than the strength of gravity does, does this mean that you ascend faster than you descend? So would a character in a game ascend at 0.02 for 10 frames then descend at 0.01 for 20 frames? ...or something like that

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No. Using Newton's equations you'll find the velocity is constantly changing with respect to time. The acceleration is constant though1. The time from start to highest point is the same as the time from highest point back to start.

Skizz

1) Assuming resitance to motion is zero.

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In the general case, ignoring air-resistance and whatnot, it should be traveling at the same speed at any given height on the way up and on the way down.

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Quote:
Original post by smitty1276
In the general case, ignoring air-resistance and whatnot, it should be traveling at the same speed at any given height on the way up and on the way down.


thats wrong, speed does change, it starts slower, reaches a trough, then increases again, the speed at the trough depends upon the angle of elevation from ground when 'jumping' if its vertical, it goes to 0 etc.

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Quote:
Original post by luca-deltodesco
Quote:
Original post by smitty1276
In the general case, ignoring air-resistance and whatnot, it should be traveling at the same speed at any given height on the way up and on the way down.


thats wrong, speed does change, it starts slower, reaches a trough, then increases again, the speed at the trough depends upon the angle of elevation from ground when 'jumping' if its vertical, it goes to 0 etc.


He meant : at a given height, the speed will be the same if you're going up or down. Let's say you jump 2 meters high, when you reach 1 meter in the air, your speed is the same than it will be when you get back to 1 meter high while falling. You could also say that the speed would be the opposite, as you'll be falling down.

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Quote:
Original post by Trillian
Quote:
Original post by luca-deltodesco
Quote:
Original post by smitty1276
In the general case, ignoring air-resistance and whatnot, it should be traveling at the same speed at any given height on the way up and on the way down.


thats wrong, speed does change, it starts slower, reaches a trough, then increases again, the speed at the trough depends upon the angle of elevation from ground when 'jumping' if its vertical, it goes to 0 etc.


He meant : at a given height, the speed will be the same if you're going up or down. Let's say you jump 2 meters high, when you reach 1 meter in the air, your speed is the same than it will be when you get back to 1 meter high while falling. You could also say that the speed would be the opposite, as you'll be falling down.


Correct, I apologize for the ambiguous phrasing.

Your speed, |v|, can be written as a function of height, h, such that:
|v| = f(h)

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