mass on light side = M
tension = T
T-Mg = Ma
T = Mg + Ma
mass on heavy side = M+m
(M+m)a = (M+m)g - T
so
(M+m)a = (M+m)g - Mg - Ma
Ma + Ma + ma = m g
(2 M+m)a = m g
a = m g/(2M+m) which we could have guessed in the beginning :)
Forces on m
Reaction force up = F
force down = m g
a down = a = m g/(2M+m)
so
mg - F = m^2 g/(2 M+m)
F = m g (1 - m/(2M+m) )
Two identical weights of mass M are linked by a thread wrapped around a frictionless pulley with
a fixed axis. A small weight of mass ‘m’ is placed on one of the weights. What is reaction force
between m and M?
3 answers
We can say that
a=mg/2M+m.....(equń1)
For block mg acts downward and F upward.
Assuming blocks move down, mg-F=ma
From equn 1 put value of 'a'
So F=2Mg/2M+m...(simple calculation)
a=mg/2M+m.....(equń1)
For block mg acts downward and F upward.
Assuming blocks move down, mg-F=ma
From equn 1 put value of 'a'
So F=2Mg/2M+m...(simple calculation)
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