Impact

[Michael A.]

Hi to all! New guy here, have a question for someone with higher math skills than mine! If a weight falls straight down 30 inches, will it fall faster or slower than a weight attached to a 15 inch lever, falling the same distance vertically? Both weights are 5 lbs.

[Grimer]

Slower.

[Michael A.]

The reason for my question is that I did some experiments on impacts. of falling weights . I made a test platform, kind of like a hammer and anvil setup. (see pics) My test subject is a .177 cal. pellet from an air gun.

[Michael A.]

sorry about that I tried to submit more than one picture, can someone tell me how to do that?

[Tarsier79]

Just look down the bottom, you may have to "click to add an attachment" again for each.

Your weight will theoretically reach the same height, but the lever also has mass, and there are resistances in the bearing, and wind resistance on the lever and the weight.

I also feel science doesn't have a perfect grasp on impact calculations.

[Michael A.]

I wanted to compare what the actual impact of a falling weight was to a static weight. I found that a weight of 5.8 ounces, falling at 90 degrees onto a .177 lead pellet was equal to a static weight of 98.6 lbs. I also measured it at 180 degrees but did not have enough weights in my shop to compare.

[Michael A.]

I thought I was posting two different pics

[Michael A.]

I measured the thickness of the pellet after each impact with a digital caliper. At 30 degree increments up to 210 degrees. I did each impact 10 times to get an average. my findings were

[ME]

If a weight falls straight down 30 inches, will it fall faster or slower than a weight attached to a 15 inch lever, falling the same distance vertically? Both weights are 5 lbs.

It depends... What do you mean by "faster"? It could be either its speed or the time to drop 30 inches.

With a lot of patience we could let the pendulum stay in it's unstable equilibrium. It could take a lot of time to reach its lowest point, theoretically it could even stay there forever.

Mathematically we can determine that in an ideal situation this potential energy leads to a predetermined end-velocity, only the levered vector will be horizontal when it fell 30 inches attached to a lever. v=√(2·g·h)

As Tarsier79 mentioned the bar has a weight, pushing the average weight a little towards the center; thus the resulting height difference will be less and (mathematical using that same formula) the speed, after a 30 inch drop, should be less.

[Michael A.]

M.E. if weight#1 and weight #2 in this picture both fall at the same time, which one will reach point "A" first?

[Michael A.]

sorry wrong picture

[Michael A.]

grrr.

[ME]

grrr.

:-)
You could edit your own post.

M.E. if weight#1 and weight #2 in this picture both fall at the same time, which one will reach point "A" first?

Straight down is faster.

When it's on a 15 inch lever and it needs to fall 30 inch then:

With a lot of patience we could let the pendulum stay in it's unstable equilibrium. It could take a lot of time to reach its lowest point, theoretically it could even stay there forever.

[Art]

Welcome Michael.A ,

If I read your intentions correctly with the experiments you are doing , you are trying to determine whether a falling weight delivers more energy by virtue of the time it takes to fall and the path through which it falls.

This is a question that some forum members have discussed over the years with different thinking and different approaches.

Pequaide , in one of the longest running threads on the forum has attempted to answer a variation of this question with the results of some of his experiments. He has been convinced for several years that it is possible to create energy by manipulating the force verses time verses pathway equation.

IMO its still an open question that needs an answer and the input of some hard data on which to base the answer .

Might I suggest that , to measure time and impact of an unencumbered falling weight , that you actually just use the weight connected to a much longer lever , - as long as you can conveniently handle . The fall of the weight along the arc of the long lever will approximate a straight line when compared to the arc followed by the weight on the 30" lever for the same distance of drop.

I think your method of measuring the impact of the falling weight is quite different and interesting .Your experiments have the potential to give some much needed data to throw some needed light on the question !.

While you will always have friction from air resistance etc to consider, this should be small enough in the actual experiments to be ignored IMO.

Nice to have you on board , please continue ! : )

[Michael A.]

Art-- Thank you for the welcome, I just thought it would be interesting to have something to compare to impact! I believe it was S,Gravesand who did tests with steel balls falling into soft clay, to test impact! I tried that but was not satisfied with the measurements, too hard to get an accurite reading!

I found it amazing that a 5.8oz. weight falling in a 15 inch radius, 90 degrees , would leave an impact equal to 98.6 lbs static.

Thats more than 270 times its own weight