Physics
(a) State two characteristics that a medium should have for propagation of sound.
(b) A pendulum has a frequency of 4 vibrations per second. An observer starts pendulum and fires a gun simultaneously. He hears the echo from a cliff after 8 vibrations of pendulum. If the velocity of sound in air is 340 ms-1, then what is the distance between cliff and observer?
Related Questions
(a) A truck and a car are running with the same speed on a highway. If the ratio of the kinetic energies is 25 : 12, then what is the ratio of their masses?
(b) Give two examples in which mechanical energy is conserved.
(a) Draw a diagram of a pulley system of velocity ratio 4. Calculate its mechanical advantage, if its efficiency is 90%.
(b) Why does a rope walker hold a long pole in his hands? Explain.
A boy tunes a radio channel to a radio station 93.5 MHz.
(a) Name and define the scientific wave phenomenon involved in tuning the radio channel.
(b) Now what is the frequency of the channel? Convert this frequency into SI unit.
(a) Explain in brief the given statement — radioactivity is a nuclear phenomenon.
(b) What is meant by nuclear waste?