The amount of air resistance<span> an </span>object<span> experiences depends on its speed, its cross-sectional area, its shape and the density of the </span>air<span>. </span>Air<span> densities vary with altitude, temperature and humidity. Nonetheless, 1.29 kg/m</span>3<span> is a very reasonable value. The shape of an </span>object affects<span> the drag coefficient (C</span>d<span>)</span>
Answer:
d- Earth revolves around the sun.
Explanation:
Earth rotation can be defined as the amount of time taken by planet earth to complete its spinning movement on its axis.
This ultimately implies that, the rotation of earth refers to the time taken by earth to rotate once on its axis. One spinning movement of the earth on its axis takes approximately 24 hours to complete with respect to the sun.
On the other hand, earth revolution can be defined as a complete trip along a path around the sun. This path is known as an orbit and it typically takes the Earth 365¼ days to complete it's journey around the Sun.
When a constellation (stars) changes its position in the sky, at the same time of the evening and over a period of several weeks; it ultimately implies or is an evidence that Earth revolves around the sun.
Answer:
Here ball and rod will repel each other as they are of similar charges
Explanation:
As we know that the two charges attract or repel each other by electrostatic force
This force is given as
so we know if two charges are similar in nature then they will repel each other and if the two charges are opposite in nature then they will attract each other
So here when rod touch the ball then it transfer its charge to the ball and due to similar charges in ball and rod they both repel each other
<h2>
Answer:442758.96N</h2>
Explanation:
This problem is solved using Bernoulli's equation.
Let 
be the pressure at a point.
Let 
be the density fluid at a point.
Let 
be the velocity of fluid at a point.
Bernoulli's equation states that 
for all points.
Lets apply the equation of a point just above the wing and to point just below the wing.
Let 
be the pressure of a point just above the wing.
Let 
be the pressure of a point just below the wing.
Since the aeroplane wing is flat,the heights of both the points are same.
So,
Force is given by the product of pressure difference and area.
Given that area is 
.
So,lifting force is 
If the substance doesn't change chemically, it is a physical reaction.
