Physics Help Forum What effect does increasing or decreasing mass of a trolley have on my value of g?

 Kinematics and Dynamics Kinematics and Dynamics Physics Help Forum

 Mar 10th 2018, 01:57 PM #1 Junior Member   Join Date: Mar 2018 Posts: 1 What effect does increasing or decreasing mass of a trolley have on my value of g? My guess is that as f=ma if mass decreases and force is equal then acceleration increases, but this seems wrong. Could someone please help and let me know what effect increasing or decreasing that mass of a trolley rolling down a ramp will have on my value of g ( acceleration due to gravity ) . Thanks
Mar 10th 2018, 02:05 PM   #2
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 Originally Posted by Hompible My guess is that as f=ma if mass decreases and force is equal then acceleration increases, but this seems wrong. Could someone please help and let me know what effect increasing or decreasing that mass of a trolley rolling down a ramp will have on my value of g ( acceleration due to gravity ) . Thanks
I'm not clear on what you mean by g. Usually g refers to the acceleration due to gravity. The value of g is independent of the mass of the body. If you simply mean acceleration and its due to something other than gravity then increasing the mass will decrease the acceleration. Simply solve for a to get

a = F/m

Therefore increase m causes a decrease in a.

 Mar 10th 2018, 02:11 PM #3 Physics Team     Join Date: Jun 2010 Location: Morristown, NJ USA Posts: 2,344 If mass increases then so does weight, and since F = weight for a falling body, changing 'm' also changes F by a similar amount and hence 'a' is constant. For a trolley rolling down an incline F is weight times the sine of the angle of the incline, so again increasing mass of the trolley should have no effect on acceleration. Of course this assumes that you can ignore the effects of friction of the wheels and wind resistance.
 Mar 12th 2018, 06:40 AM #4 Senior Member     Join Date: Jun 2016 Location: England Posts: 883 What ChipBs post implies (though it does not explicitly state it) is that Any change in the Mass is directly (and precisely) mirrored by a change in the Force. This means that the acceleration remains the same. Indeed Mass and Weight are often (rather incorrectly) used as direct analogues for each other, because "g" remains pretty much the same for all locations on Earth. On the moon the Mass remains the same (as on Earth) but the Weight changes. This is because "g" on the moon is (about) six times less than "g" on Earth. __________________ ~\o/~

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