simple....

can anyone please.....

mohit i think the answer to ur second problem should be that :
the total maximum compression of the spring = mg/k + √(2mgh/k).(this answer includes the compression caused by the plate)if u have got the answer just let me know if this is correct..

i got the first question answer

but for second question ans given is

(mg/k)+((2mg+√m²g²+2kmgh)/k)

please give method to do it.

please give at least some method of doing 2nd question.

i'll outline the method,
see that the velocity of particle just b4 collision is √2gh,
since its an inelastic collision velocity of the system later will be 1/2*√2gh
now conserve energy at this point and the point where the system momentarily has 0 velocity. add mg/k