Question Details

A satellite is launched into a circular orbit of radius R around the earth. A second satellite is launched into an orbit of radius (1.01) R. The period of the second satellite is larger than that of the first one by approximately

Options

A

0.5%

B

1.0%

C

1.5%

D

3.0%

Correct Answer :

1.5%

Solution :

The correct option is 1.5%.

To find the fractional change in the orbital period of the satellite when its orbital radius increases, we can use Kepler's Third Law of Planetary Motion. Kepler's Third Law states that the square of the orbital period of a satellite (T) is directly proportional to the cube of the radius of its circular orbit (r). This can be mathematically expressed as:


T2r3

Taking the square root on both sides gives:


Tr3/2

We can write this as an equation with a constant of proportionality k:


T=kr3/2

Taking the natural logarithm (ln) on both sides of the equation, we get:


ln(T)=ln(k)+32ln(r)

To find the relationship between small fractional changes in T and r, we differentiate both sides of the equation:


dTT=32drr

For small changes, we can approximate the differentials with finite changes (Δ):


ΔTT32Δrr

According to the problem, the first satellite has a radius of r1=R, and the second satellite has a radius of r2=1.01R.
The change in the orbital radius is:


Δr=r2-r1=1.01R-R=0.01R

The fractional change in the radius is:


Δrr=0.01RR=0.01

Substituting this fractional change into our approximation equation:


ΔTT32×0.01=0.015

To convert this fractional change to a percentage, we multiply by 100%:


Percentage increase in period=0.015×100%=1.5%

Thus, the period of the second satellite is larger than that of the first one by approximately 1.5%.

Unlock Our Free Library

Access expert-curated educational resources and study materials—completely free.

Discover more resources

You may also like

Mock Tests

View All
  • JEE
  • intermediate
  • 3 hours
  • chemistry, mathematics, physics

  • JEE
  • intermediate
  • 3 hours
  • chemical engineering, mathematics, physics