min H

A spring mass system is held at rest with the spring relaxed at height H above the ground.Determine min. value of H so that given system has tendency to rebound after hitting the ground.
Given coeff of restitutuion between m2 and ground is zero.

5 Answers

1
dimensions (dimentime) ·

(kx)2=2m1g(kx+m2g)+(m2g)2

kx2=2m1gH

just solve for H

u will get the ans

24
eureka123 ·

tell me how did u get those 2 eqns????????????

1
Diptosh ·

I can tell you the thing ,
the condition that the lower block rebounces is
x > M2g/k because just draw the free body diags , statics problems thats the key
1/2 M1 v^2 = 1/2 kx^2 + M1 gx

also , kx = M2g

So ,
2M1 gh = k(M2g/k)^2 + 2M1g(M2 g/k) this should give the answer !

Please tell me if they are correct !! Been so out of touch :(

62
Lokesh Verma ·

Here x will be such that kx=m2g

so x= m2g/k

Energy just after colission (state 2 in the figure) (The KE of the lower mass gets lost!)
= M1gH

Energy just at extension x will be M1gx+1/2kx2

We know x..

So we know H!

btw i think i am getting the same answer as Diptosh :)

24
eureka123 ·

thanxx

Your Answer

Close [X]