Answer:
<em> The object has frequency of 2 Hz and time period of 0.5 s.</em>
Explanation:
<em>Frequency</em> is defined as number of oscillation per second ie back and forth swings done in single second.
Here it is given that the object oscillates 20 times in 10 seconds.
So f =
= 2Hz
The <em>time period</em> is defined as time taken by the object to complete one full oscillation.
T = 
T=
=0.5 s
<em>Thus the object has frequency of 2 Hz and time period of 0.5 s.</em>
Answer:
gravitational force
electrostatic force
Explanation:
The forces that balloons may exert on each other can be gravitational pull due to the mass of the balloon membrane and the mass of the gas contained in each. This force is inversely proportional to the square of the radial distance between their center of masses.
The Mutual force of gravitational pull that they exert on each other can be given as:

where:
gravitational constant 
are the masses of individual balloons
the radial distance between the center of masses of the balloons.
But when there are charges on the balloons, the electrostatic force comes into act which is governed by Coulomb's law.
Given as:

where:

are the charges on the individual balloons
R = radial distance between the charges.
Answer:
C
Explanation:
Angular momentum is the product of moment of inertia and angular velocity.
L = I × ω
Since the planet follows a stable circular orbit, I and ω are constant and non-zero. Therefore, the angular momentum is constant and non-zero.