The angular speed \( \omega \) of an object is given by:
\(\omega = \frac{2\pi}{T},\)
where \( T \) is the time period.
For the moon:
- \( T_{\text{moon}} = 27 \, \text{days} \).
For the earth:
- \( T_{\text{earth}} = 365 \, \text{days} \).
Since the moon takes less time to complete one orbit around the earth compared to the earth's revolution around the sun, \( T_{\text{moon}} < T_{\text{earth}} \). Therefore:
\(\omega_{\text{moon}} > \omega_{\text{earth}}.\)
This makes both the assertion and the reason correct, and the reason is the correct explanation of the assertion.
The correct option is (A) : Both Assertion (A) and Reason (R) are the true and Reason (R) is a correct explanation of Assertion (A).
The height from Earth's surface at which acceleration due to gravity becomes \(\frac{g}{4}\) is \(\_\_\)? (Where \(g\) is the acceleration due to gravity on the surface of the Earth and \(R\) is the radius of the Earth.)
The work which a body needs to do, against the force of gravity, in order to bring that body into a particular space is called Gravitational potential energy. The stored is the result of the gravitational attraction of the Earth for the object. The GPE of the massive ball of a demolition machine depends on two variables - the mass of the ball and the height to which it is raised. There is a direct relation between GPE and the mass of an object. More massive objects have greater GPE. Also, there is a direct relation between GPE and the height of an object. The higher that an object is elevated, the greater the GPE. The relationship is expressed in the following manner:
PEgrav = mass x g x height
PEgrav = m x g x h
Where,
m is the mass of the object,
h is the height of the object
g is the gravitational field strength (9.8 N/kg on Earth) - sometimes referred to as the acceleration of gravity.