Pushing vs pulling a trolley

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Humberto

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Consider a trolley of the type shown here: http://www.castorandladder.co.za/trolleys.htm.

When pushing the trolley, it seems to hit surface bumps harder than when pulling it. I wondered why this should be the case; after all, isn't it the same force that is applied whether pushing or pulling?

I think the reason why the ride is harsher when pushing it is that there is both a horizontal and vertical component to the force that is applied. When pushing the trolley, you are partially pushing it into the ground, while when pulling it, you are partially pulling it away from the ground.

I also noticed something else that intrigued me. When walking normally, your left arm swing forwards and backwards with your right foot, and your right arm swings forwards and backwards with your left foot. When your left arm swings forwards, your right arm swings backwards.

Now walk with your arms swinging at the same speed and through the same arc as normal, but swinging together: both arms swinging forwards at the same time, or backwards at the same time. When you walk like this, even though you're swinging your arms through the same arc at the same speed as normal, it feels like you're using more force.
 
Humberto said:
I think the reason why the ride is harsher when pushing it is that there is both a horizontal and vertical component to the force that is applied. When pushing the trolley, you are partially pushing it into the ground, while when pulling it, you are partially pulling it away from the ground.
Click to expand...

That's pretty much it I reckon, force vectors.

As for the arms & legs thing I reckon it has to do with balance offset, just like how some animals use their tails (cheetah etc). The feeling of requiring more force might be related how your muscle groups work together opposing each other under certain actions.
 
I always find the getting other people to move for me requires the least amount of force. :p
 
I haven't given't much thought to the arm-swinging-question ... but I have experienced the same issue regarding the pushing and pulling of a cart ... whether it be a shopping trolley or something else.

If the Force that comes into play isn't the initial force but the reactionary force ... or the direction of the force at play after any impact.

By pushing the direction of the force (after impact) is directed downwards (because of the geographics of the obstacle and of course gravity ... the weight of the trolley is also a factor, if not thee factor) and when by pulling the direction of force is directed upwards.
 
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When you pushing, there is a lot of the force focused down, which means more pressure towards the ground...
whereas when pulling, alot of the pressure you are applying is in an upward direction, so you tend to "pull" the trolley over the bump, instead of pushing it into them.
Imagine trying to push the trolley up stairs, compared to pulling it up stairs...

Well, thats how i see it :)
 
People always look at me funny when I walk through the store pulling the cart along behind me.
I do it on purpose.

Also: A post by Humberto that doesn't ask a strange question? :erm:

Something's fishy!

PS: The arm-swinging thing is a matter of balance. It's how our locomotion developed for us to walk on two legs and run on two legs.
When you swing both your arms together, or don't swing them at all, you are exerting more energy to contradict your body's natural gait and movement, so yes, you are using 'more force' to do it, where force = energy.
 
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You are right about the trolley. Another factor as well is gravity. When an object is being pushed the front is falling down. When it is pulled it is kept straight.

Walking is a balancing act. We are throwing ourselves forward of balance and then pushing up.
 
You can't drift a trolley when you're pulling it... Just saying. ;)
 
greg0205 said:
You can't drift a trolley when you're pulling it... Just saying. ;)
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I concur ;)
Pulling someone up a ramp in a trolley vs pushing them down said ramp loses much of the entertainment value as well.
 
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I've been known to jump in a store trolley while shopping on an early Saturday morning.
Funny how a non-stop night of partying and alcohol always seems to be the common denominator to it though :rolleyes: :erm:
 
I run a S#$% store up here, once a year we have what we call the Managers Xmas Party, each Manager gets to invite two Guests, when the store closes in the evening, we lay on platters and booze, we party up on the tills and after a few hours we start the trolley races..... we place shorts (Jagermeisters/Tequila etc ) at various stop points and then you put your partner in the trolley and the racing commences.... I seen trolleys do incredible things, like taking out the dog food shelf, going the entire length of the shelf run on two wheels...... great fun...


Oh! How do you make a trolley go faster?

Push it down the escalator......

:whistle:
 
Mortymoose said:
I run a S#$% store up here, once a year we have what we call the Managers Xmas Party, each Manager gets to invite two Guests, when the store closes in the evening, we lay on platters and booze, we party up on the tills and after a few hours we start the trolley races..... we place shorts (Jagermeisters/Tequila etc ) at various stop points and then you put your partner in the trolley and the racing commences.... I seen trolleys do incredible things, like taking out the dog food shelf, going the entire length of the shelf run on two wheels...... great fun...


Oh! How do you make a trolley go faster?

Push it down the escalator......

:whistle:
Click to expand...

NICE!

Invite me this year! :p :D
 
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