11Bhaiya i found it while going thru the book --
"200 Puzzling problems In Physics"
A small object is at rest on the edge of a horizontal table.It is pushed in such a way that it falls off the other side of the table,which is 1m wide in 2s.Does the object have wheels ??
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9 Answers
1no
cuz if it had wheels then it wud hav had fallnon d same side
nw as it dnt hav wheel .itz due to frictio dat it falls ..on d oder side
62I dont think we can say much about this ronald..
As far as I understand it could have a wheel or could not.. in both cases it can fall on the other side...
Where did you get this problem from?
1i thnk it depends on friction...of the table...and if mass is given..
and thn we can use the fact tht rolling friction is least....
11
66The problem is more of an estimation rather than a deterministic one. The average speed of the object is 1/2 m/s. Assuming it decelerated uniformly we also have
v_\mathrm{average}=\dfrac{1}{2}(v_\mathrm{inital}+v_\mathrm{final})
and so the initial speed could not have exceeded 1m/s. (WHY?)
Thus the speed of the body decreases by at least 1m/s in 2 s. Thus its retardation is at max 0.5 m/s2. i.e. approximately g/20. As such the coefficient of kinetic friction between the object and the table cannot exceed 1/20. This is quite small and therefore it is very likely that the object does not slide but a part or all of it rolled. Hence, most probably the object has wheels.
11Kaymant Sir , I could not understand as to why the initial speed of the object can not exceed 1 m/s.... Sir could you please explain that part....
11@ Aditya- because Vfinal can never be less than 0.
Vavg is given =1/2
Therefore,,Vi can never be more than 1.