When a person is standing on earth, the treesand houses appera stationary to mim. However, when he is sitting in a running train all these obects appear to move in bakward direction. Why?

Explain why when a person stands on a cushion , the depression is much more than when he lies down on it .

Two trains A and B are moving with same speed of 100km//hr .Train A moves towards east and train B moves towards west.An an instant when the trains are moving side by side, an aeroplane files above the trains horizontally.For the passengers in the train A , the plane appears to fly from North to South direction.For the passengers in the train B , the plane appears to fly in a direction making an angle 60^(@) to North-South direction.

Explain why, when a person stands on a cushion, the depression is much more than when he lies down on it.

Statement I: A person is standing near a railway trach. A train is moving on the track. As the train is approaching the person, apparent freqeuncy keeps on increasing and when the train has passed the person, then apparent freqeuncy keeps on decreasing. Statement II: When train is approaching the person then, f=f_0[(c )/(c-u)] and when train is moving away from person f=f_0[(c )/(c+u)] Here, c is velocity of sound u is velocity of train and f_0 is original frequency of whistle.

When a boy is stationary, he observes that rain drops are falling at 30^(@) to vertical direction. When he starts running with speed 10m/s , he observed that rain drops are falling vertically downwards. Calculate the actual velocity of rain drops.

Two train whistles have identical frequencies of 180 Hz. When one train is at rest in the station and the other is moving nearby, a passenger standing on the station platform hears beats with a frequency of 2.00 beats/s when the shistles operate together. What are the two possible speeds and direction the moving train can have? speed of sound is 343 m/s.

A man is standing between a stationary source and cliff. When he starts moving along line joining him and source, he hears 10 beats per second. The velocity of mas is [frequency of source=600Hz, velocity of sound=330 ms^(-1) ]

When two sets of progressive wave trains of the same type, having same amplitude an same time period, travelling with same speed along the same straight line in opposite directions superimpose, a new set of waves are formed. These are called stationary waves or standing waves. The resultant waves do not propagate in any direction, nor there is any transfer of energy in the medium. Read the above passage and answer the following questions: (i) Stationary waves are characterised by nodes and antinodes. What are these points ? (ii) What is the total energy associated with a stationary wave ? What values of life do you learn from this ?

A train is running at a constant speed of 90 km/h on a straight track. A person standing at the top of a boggey moves in the direction of motion of the train such that he covers 1 meters on the train each second. The speed of the person with respect to ground to -