Question

The distances of two planets (Neptune and Saturn) from Sun are 10^13 and 10 ^12 m respectively. The ratio of time periods of revolution around sun for the planets is :
1: 100
2: 1/√10
3: √10
4: 10√10

Choose the correct option.
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Answer 1

Answer:

option 4:

10*10^1/2

Explanation:

Using Kepler's 3rd law,

T^2 =k*r^3

where r is distance.

T(neptune)=(10^13)^3/2

T(Saturn) = (10^12)^3/2

T(neptune)/T(Saturn)= {(10^13)^3/2}  / {(10^12)^3/2}

T(neptune)/T(Saturn)=10^3/2

T(neptune)/T(Saturn)=10*10^1/2