::
:::
Two springs fixed at one end are stretched by 5cm and 1cm, respectively, wher
masses 0.5 kg and 1 kg are suspended at their lower ends. When displaced
slightly from their mean positions and released. They will oscillate with time
periods in the ratio:
A) 1:2
B) 1:2
C) 2:1
D) 2:1
Answers
Answer:
The ratio of the time period is 1:√2.
Explanation:
Given that,
First mass = 0.5 kg
Second mass = 1 kg
First stretch = 5 cm
Second stretch = 10 cm
We need to calculate the spring constant
Using relation of restoring and newton's second law
kx=mgkx=mg
k=\dfrac{mg}{x}k=
x
mg
For first spring,
k_{1}=\dfrac{0.5\times9.8}{5\times10^{-2}}k
1
=
5×10
−2
0.5×9.8
k_{1}=98\ N/mk
1
=98 N/m
First second spring,
k_{2}=\dfrac{1\times9.8}{10\times10^{-2}}k
2
=
10×10
−2
1×9.8
k_{2}=98\ N/mk
2
=98 N/m
We need to calculate the ratio of time period
Using formula of time period
T=2\pi\sqrt{\dfrac{m}{k}}T=2π
k
m
For first spring,
T_{1}=2\pi\sqrt{\dfrac{0.5}{98}}T
1
=2π
98
0.5
....(I)
For second spring,
T_{2}=2\pi\sqrt{\dfrac{1}{98}}T
2
=2π
98
1
.....(II)
divided equation (I) by (II)
\dfrac{T_{1}}{T_{2}}=\sqrt{\dfrac{0.5\times98}{1\times98}}
T
2
T
1
=
1×98
0.5×98
\dfrac{T_{1}}{T_{2}}=\dfrac{1}{\sqrt{2}}
T
2
T
1
=
2
1
Hence, The ratio of the time period is 1:√2.