# Calculating impact force?

1. Dec 29, 2009

### alexa23

calculating impact force??

I need help calculating impact force. Here's all the information I have:

the object weighs 180 pounds
being dropped from a height of 11 feet

I'm not completely sure if the force can be determined from that. I'm having a hard time figuring it out for some reason.

2. Dec 30, 2009

### Tominator

Re: calculating impact force??

Hi Alexa
I recommend you to read forum rules before posting because your thread seems like a homework and homeworks are discussed in other forum.
By the way welcome to PF

3. Jan 6, 2010

### waynexk8

Re: calculating impact force??

Hi all,

I would like to ask the same thing, and first to prove its not homework, first I am 48, and second, we were wondering how mush force the muscles would be taking on the transition from negative to positive, like in strength training, and repping a barbell up and down. We call this transition MMMs {Momentary Maximum Muscle Tensions}

These tensions or forces are as you imagine the highest there is in the whole rep. {repetition} As when you are on the eccentric of the rep, you are still controlling it down, but when a given load is lowed quite fast, the acceleration component means that the forces exerted on the load (and thereby by the muscles) by far exceeds the nominal weight of the load.

Would it be possible to work out the force of ??? Let’s say a 90kg weight, dropping at .5 of a second for 1m, please ???

Wayne

4. Jan 6, 2010

### Redbelly98

Staff Emeritus
Re: calculating impact force??

More information is needed. Specifically, either how long or over what distance is the object brought to a stop? Note, this is different than the time or distance that the object is falling.

5. Jan 7, 2010

### waynexk8

Re: calculating impact force??

Hmm, as you can see this is a bit tricky to say, as when you are repping up and down with a barbell it quite hard to tell.

Therefore, what we say the last fifth of the eccentric, and that would also be one fifth of .5 of a second.

And thx for you time.

Wayne