1. ## mechanics elastic springs

A new bulb with a bayonet fitting is to be inserted into a vertical lamp holder the mass of the bulb is 40gram. To insert the bulb it is first placed in the holder so that it rests on the two vertical springs it then has to be pushed down 6mm against the springs and twisted then when it is released it rises 2mm and is held firm by the pins which fit into the slots in the holder the maximum force you need to exert during the process is 2 newtons Find the force holding the bulb in position.

what i have done so far
since there are two springs the force acting on it will be divided by 2

formula that is to be used T=(lambda*x)/l where T is tension. lambda is the modulus of elasticity
x is extension l is the original length

why is answer 4/3 N help

2. ## Re: mechanics elastic springs

Hint, Force applied = Force of gravity + Force of spring. I think you can solve this using Conservation of Energy.

3. ## Re: mechanics elastic springs

no bro we dont have to use the conservation of energy examiner says u dont and shouldnt use energy conservation u would complex thing but and we can use f=kx or f=lamda*x/l
i thing the total force is 2+(40*10^-3)=2.04
since there are two springs each get a force of 2.04/2=1.02
1.02=kx
1.02=k*6*10^-3
k=170
T=170*2*10^-3

4. ## Re: mechanics elastic springs

there you go
Originally Posted by sakonpure6
Hint, Force applied = Force of gravity + Force of spring. I think you can solve this using Conservation of Energy.