Sound travels in air if
(a) particles of medium travel from one place to another
(b) there is no moisture in the atmosphere
(c) disturbance moves
(d) both particles as well as disturbance travel from one place to another.
In SONAR, we use
(a) ultrasonic waves
(b) infrasonic waves
(c) radio waves
(d) audible sound waves
A key of a mechanical piano struck gently and then struck again but much
harder this time. In the second case
(a) sound will be louder but pitch will not be different
(b) sound will be louder and pitch will also be higher
(c) sound will be louder but pitch will be lower
(d) both loudness and pitch will remain unaffected
Note is a sound
(a) of mixture of several frequencies
(b) of mixture of two frequencies only
(c) of a single frequency
(d) always unpleasant to listen
A light and a heavy object have the same momentum. Find out the ratio of
their kinetic energies. Which one has a larger kinetic energy?
If an electric iron of 1200 W is used for 30 minutes everyday, find electric
energy consumed in the month of April.
Is it possible that an object is in the state of accelerated motion due to external force acting on it, but no work is being done by the force. Explain it with an example.
The velocity of a body moving in a straight line is increased by applying a
constant force F, for some distance in the direction of the motion. Prove
that the increase in the kinetic energy of the body is equal to the work done
by the force on the body.
The weight of a person on a planet A is about half that on the earth. He can
jump upto 0.4 m height on the surface of the earth. How high he can jump
on the planet A?
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