Push the Spring for cube lifting...
Classical Mechanics
Level
3
A system consists of two cubes of m1 and m2 respectively connected by a spring of force constant K
.The Force(F) that should be applied to the upper cube for which the lower one just breaks contact with the surface after the force is removed is:
(m1+m2)g
m1g
1/2(3m1+2m2)g
2(m1+m2)g
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1 solution
I use a positive sign in the spring force to express compression and a negative sign to express stretching.
The spring force when m 1 is at its highest point should be equal to − m 2 g in order to just lift m 2 up. In the equilibrium position, the spring force is + m 1 g . So the amplitude of the force about the equilibrium position has to be the difference if these;: + m 1 g − − m 2 g = ( m 1 + m 2 ) g .