Answer:
Volume of balloon = 1000 cm^3
Explanation:
The head of a normal person can be assumed as a sphere with radius 10 cm.
Volume of sphere
, where r is the radius.
We have approximate radius = 10 cm.
Approximate volume of head 
In the given options the closest value to the approximate volume is 1000 cm^3.
So, volume of head = Volume of balloon = 1000 cm^3
Find Acceleration




Now
Using 1st equation of kinematics





Since static friction is the minimum force required to just start the motion of a stationary object.
Here if we need to start an object from rest then we required F = 700 N
So for the first part of the above problem Force will be F = 700 N
Now if the box is already moving then we will have to use kinetic friction force between box and floor
now we can write the equation of net force as

here



now we will have


Answer:
Jovian planets
Explanation:
The gas giants, or jovian or extra-terrestrial planets are predominantly made up of gases than liquids and solids.
They are located beyond the fringes of the Asteroid belts which is the zone between the inner and outer planets.
The outer planets are Jupiter, Saturn, Uranus and Neptune. These planets are made up of gases predominantly hydrogen and helium.
The inner planets called terrestrial planets are solids balls of rocks. These planets are Mercury, Venus, Earth and Mars.