Page 3 - LN

• Springs in Series
If two springs, having spring constant k 1 and k 2, are joined in series, the spring constant of the
combination is given by

• Springs in Parallel
If two springs, having spring constants k 1 and k 2, are joined in parallel, the spring constant of the
combination is given by
k = k 1 + k 2
• When one spring is attached to two masses m 1 and m 2, then

• Simple Pendulum
A simple pendulum is the most common example of bodies executing S.H.M. An ideal simple
pendulum consists of a heavy point mass body suspended by a weightless in extensible and
perfectly flexible string from a rigid support about which it is free to oscillate.
• The time period of simple pendulum of length ‘l’ is given by

The time period of a simple pendulum depends on
(i) length of the pendulum and
(ii) the acceleration due to gravity (g).
• A second’s pendulum is a pendulum whose time period is. 2s. At a place where g = 9.8 ms , the
-2
length of a second’s pendulum is found to be 99.3 cm (= 1 m).
• If a liquid of density p oscillates in a vertical U-tube of uniform cross sectional area A, then the
time period of oscillation is given by