Answer:
3.25 seconds
Explanation:
It is given that,
A person throws a baseball from height of 7 feet with an initial vertical velocity of 50 feet per second. The equation for his motion is as follows :

Where
s is the height in feet
For the given condition, the equation becomes:

When it hits the ground, h = 0
i.e.

It is a quadratic equation, we find the value of t,
t = 3.25 seconds and t = -0.134 s
Neglecting negative value
Hence, for 3.25 seconds the baseball is in the air before it hits the ground.
Nitrogen
Explanation:
Adding one proton to a carbon atom makes Nitrogen.
A quick introspection on atoms:
- An atom is made up of three fundamental particles.
- They are protons, neutrons and electrons.
- The protons are positively charged and the neutrons do not carry any charges.
- Electrons are negatively charged.
The difference between an atom and another is the number of protons in them. This is the atomic number.
The periodic table of element is a list of elements arranged based on the number of protons they have. Every element on the table has unique number of protons which makes it differ from another.
- Atoms do not readily lose their protons because they are held by nuclear forces in the nucleus of an atom.
When an element gains a proton, it becomes another element.
Carbon has proton number of 6
If a proton is added to it, it becomes 7
This is the proton or atomic number of nitrogen.
Learn more:
Atomic number brainly.com/question/5425825
#learnwithBrainly
Eh not really sure bout this one
We know that momentum = mass times velocity
So a. 720 kgm/s