Explanation:
We start by using the conservation law of energy:

or

Simplifying the above equation, we get

We can rewrite this as

Note that the expression inside the parenthesis is simply the acceleration due to gravity
so we can write

where
is the launch velocity.
The process of formation of a reddish-brown substance on the surface of the iron objects in the presence of flaky moisture and air is called rusting.
Answer:

Explanation:
Given that,
The speed of a driver, v = 80 km/h = 22.22 m/s
The mass of the truck, m = 2000 kg
We need to find how much internal energy is produced. The internal energy produced by a truck is its kinetic energy and it is given by :

or

So,
of internal energy is produced.
Similar elements with similar properties were in the same groups and periods for instance lithium(Li) and sodium(Na) are alkaline metals and so belong to the same group (that is group 1).Also Hydrogen(H) and Helium(He) both have only one shell or energy level and so belong to the same period.