The Special Theory of Relativity Physics - The Special Theory of Relativity

If the speed of a rod moving at a relativistic speed parallel to its length is doubled,

1. The length will become half of the original value.
2. Mass will become double of the original value.
3. The length will decrease.
4. The mass will increase.

Mark the correct statements:

1. Equations of special relativity are not applicable for small speeds.
2. Equations of special relativity are applicable for all speeds.
3. Nonrelativistic equations give exact result for small speeds.
4. Nonrelativistic equations never give exact result.

A charged particle is projected at a very high speed perpendicular to a uniform magnetic field. The particle will:

1. Move along a circle.
2. Move along a curve with increasing radius of curvature.
3. Move along a curve with decreasing radius of curvature.
4. Move along a straight line.

As the speed of a particle increases, its rest mass:

1. Increases.
2. Decreases.
3. Remains the same.
4. Changes.

An aeroplane travels over a rectangular field 100m × 50m, parallel to its length. What should be the speed of the plane so that the field becomes square in the plane frame?

By what fraction does the mass of a spring change when it is compressed by 1cm? The mass of the spring is 200g at its natural length and the spring constant is 500N/m.

At what speed the volume of an object shrinks to half its rest value?

Find the increase in mass when 1kg of water is heated from 0^°c to 100^°C. Specific heat capacity of water = 4200J/kg-K.

A 100W bulb together with its power supply is suspended from a sensitive balance. Find the change in the mass recorded after the bulb remains on for 1 year.

The guru of a yogi lives in a Himalyan cave, 1000km away from the house of the yogi. The yogi claims that henever he think.a about hi a guru, the guru unmediately knows about it. Calculate the minimum possible time interval between the yogi thinking about the guru and the euni knowing about it.

By what fraction does the mass of a boy increase when he starts running at a speed of 12km/h?

What is the kinetic energy of an electron in electronvolts with mass equal to double its rest mass?

The speed of light in glass is 2.0 × 10¹m/s. Does it violate the second postulate of special relativity?

A uniformly moving train passes by a long platform. Consider the events' engine crossing the beginning of the platform' and 'engine crossing the end of the platform'. Which frame (train frame or the platform frame) is the proper frame for the pair of events?

Through what potential difference should an electron be accelerated to give it a speed of: 

1. 0.6c
2. 0.9c
3. 0.99c

A person travelling in a fast spaceship measures the distance between the earth and the moon. Is it the same, smaller or larger than the value quoted in this book?

The energy from the sun reaches just outside the earth's atmosphere at a rate of 1400W/m². The distance between the sun and the earth is 1.5 × 10¹¹m.

1. Calculate the rate at which the sun is losing its mass.
2. How long will the sun last assuming a constant decay at this rate? The present mass of the sun is 2 × 10⁸⁰kg.

Find the speed of an electron with kinetic energy:

1.  1eV
2. 10keV
3. 10MeV

A suitcase kept on a shop's rack is measured 50cm × 25cm × 10cm by the shop's owner. A traveller takes this suitcase in a train moving with velocity 0.6c.
If the suitcase is placed with its length along the train's velocity, find the dimensions measured by:

1. The traveller and.
2. A ground observer.