A girl is swinging on a swinging plate form in sitting position when the girl stands up then the period of swinging?

• Will not change

•  Will depend on height of girl

• Will be longer

•  Will be shorter

The displacement of the motion of a particle is represent by a equation  $\mathrm{Y}=\mathrm{ASin\omega t}+\mathrm{BCos\omega t}$. The motion of the particle is

• SHM with amplitude $\sqrt{{\mathrm{A}}^2+{\mathrm{B}}^2}$

• SHM with amplitude A+B

• SHM with amplitude A

• Oscillatory but not in SHM

143.

Standing wave are produced in a 10 m long stretched string. If the string vibrates in 5 segments and the wave velocity is 20 m/s. The frequency is

• 10Hz

• 5Hz

• 4Hz

• 2Hz

A steel wire 0.5 m long has a total mass 0.01 kg and stretched with a tension of 800 N. The frequency with which it vibrates in its fundamental note will be

• 4Hz

• 2Hz

• 200Hz

• 160Hz

 A cord attached to a vibrating tuning fork is divided into six segments under tension of 36 N. It will be divided into four segments, if the tension is

• 48N

• 81N

• 24N

• 16N

The equation of travelling wave is y= 60 cos (1800 t-6x) where y is in micron and t in second and x in metre. The ratio of maximum particle velocity to velocity of wave propagation is

• 3.6

• 3.6$\times {10}^{-4}$

• $3.6\times {10}^{-11}$

• $3.6\times {10}^{-6}$

In a sinusoidal wave, the time required for a particular point to move from maximum displacement to zero displacement is 0.170.The frequency of the wave will be

• 2.94Hz

• 0.73Hz

• 0.36Hz

• 1.47Hz

A resonance air column of length 40 cm resonates with tunning fork of frequency 450Hz. Ignoring end corrections , the velocity of sound in air will be

• 1020m/s

• 920m/s

• 820m/s

• 720m/s

A simple pendulum of length l has a maximum angular displacement θ. The maximum kinetic energy of the bob is

• mgl (1-cosθ)

• 0.5 mgl

• mgl

• 0.5 mgl

Equations of motion in the same direction are given by

$$\begin{gathered} {\mathrm{y}}_1 =2\mathrm{\alpha } \sin \left(\mathrm{\omega t} -\mathrm{kx}\right) \\ {\mathrm{y}}_2 =2\mathrm{\alpha } \sin \left(\mathrm{\omega t} -\mathrm{kx}-\mathrm{\theta }\right) \end{gathered}$$

The amplitude of the medium particle will be

• $2\mathrm{\alpha } \mathrm{cos\theta }$

• $\sqrt{2}\mathrm{\alpha } \mathrm{cos\theta }$

• $4\mathrm{\alpha } \cos \frac{\mathrm{\theta }}{2}$

• $\sqrt{2}\mathrm{\alpha } \cos \frac{\mathrm{\theta }}{2}$