Work in general is given by W=F·d where F is the force vector and d is the displacement vector. The dot symbol is the dot product which is a measure of how parallel two vectors are. It can be replaced by the cosine of the angle between the two vectors and the vectors replaced by their magnitudes. If F and d are parallel then the angle is zero and the cosine is unity. So in this case work can be defined as the product of the magnitudes of the force and distance:
W=Fd
Question no. 1. Compare the planets Mars and Saturn. Describe how their common characteristics are similar:
Answer: Our solar system is located in the outer spiral arm of the milky way galaxy. our solar system has one sun and nine revolving planets and . namely
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
- Pluto (small planet usually refer as dwarf)
Each star has its on moon/moons and has its own characteristics i.e , planet must be a celestial body , must have orbit around sun, have enough mass for self gravity, big enough to have gravity that clear its path from other same size object close to its orbit around sun.
Mars is the fourth from the sun and sixth is the Saturn from the sun in our solar system.
<u>Common in Characteristics of Mars and Saturn:</u>
- Mars and Saturn both have celestial body.
- Mars and Saturn both have enough mass for the gravity to get rid of rigid body forces.
- Mars and Saturn both revolve around the sun in their own orbits.
- Mars is the second smallest in the solar system while Saturn is second largest in the solar system.
- Mars and Saturn both have their own moons. Mars has two while Saturn has 83 moons
- Mars and Neptune both do not support life.
Question no. 2. Compare the planets Earth and Neptune. Describe how are they different from each other
Answer:
Earth our home planet is the third from the sun and Neptune on the other hand is the eighth from the sun in the solar system.
<u>Common differences between Earth and Neptune</u>
- Earth is the terrestrial planet while Neptune (Ice giant) is the Jovian planet.
- Earth has no ring around it, Neptune has ring around it.
- Earth is closer to the sun and Neptune is far distant from the sun.
- Earth consists of rocks and metals on the other hand Neptune contain gases
- Earth is smaller than the Neptune in the solar system.
- Earth rotates slower and Neptune rotates faster.
To solve this problem we will apply the principle of conservation of energy. For this purpose, potential energy is equivalent to kinetic energy, and this clearly depends on the position of the body. In turn, we also note that the height traveled is twice that of the rigid rod, therefore applying these concepts we will have
Therefore the minimum speed at the bottom is required to make the ball go over the top of the circle is 4.67m/s
It hardens because you are pressing it against something.
We have to convert Gm/s to m/s.
As 
Therefore the speed of light in vacuum,
Thus, the speed of light in m/s is 
