Simple Harmonic Motion - Two springs attached

AI Thread Summary
The discussion focuses on a homework problem involving two springs with different lengths and force constants, where one spring is 10 cm long with a force constant of 150 N/m and the other is 20 cm long with a force constant of 100 N/m. The combined system is pulled to a total length of 50 cm, leading to calculations for the amount each spring is stretched and the period of oscillation for a 400g block placed between them. The user initially calculated the force and stretch for each spring correctly, finding the total stretch to be 0.2 m and the force to be 12 N. For the period of oscillation, they correctly combined the spring constants to find an effective spring constant of 250 N/m, resulting in an approximate period of 0.25 seconds. The responses confirm that the user's calculations are correct.
Koey
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Yeah I got this question and I'm just wondering if I'm doing it right.

Homework Statement



A spring normally 10cm long and whose force constant is 150 n/m is connected to another spring normally 20cm long and whose force constant is 100 n/m. The combination is then pulled out so that its ends are 50cm apart.

a) find the amount each spring is stretched.

b) a 400g block on a frictionless surface is attached between the springs. find its period of oscillation.

Homework Equations



T = 2pi sqroot(m/k)
F = kx

The Attempt at a Solution



Well I tried something no idea if it is correct..

a) Made Xtotal = 0.2 because I subtracted the spring lengths
X1 = F/150
X2 = F/100
(F/150)+(F/100) = 0.2
F = 12
Then I subbed F values back into the original 2 equations to get X values.

b) For this question I assumed the combined force constant for the springs would be additive so
k = 250 n/m
m = 0.4 kg

T = 2pi sqroot (m/k)
= 2pi sqroot (0.4/250)
= 0.25s (approx)

Need to know if I'm doing this right or horribly wrong..

Cheers
 
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It is OK.

ehild
 
Does that means I've done it right??
 
Koey said:
Does that means I've done it right??

YES! :smile:

ehild
 
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