Answer:110.25 m
Explanation:v^2 = u^2 + 2as
21^2 = 0 - 2*2*s
s = 441/4
s=110.25 m
Newton's second law of motion states the following:

In which

is the force,

is the mass, and

is the acceleration of the object.
So, the answer is B.
Answer:

Explanation:
When a person shouts it emits 1 W of energy as sound waves, P = 1 W
Let I is the sound intensity 1 meters from such a person. We know that the power per unit area is called the sound intensity of the person. Its formula is given by :



So, the sound intensity of such a person is
. Hence, this is the required solution.
Answer:
Question 1: protons and electrons
Question 2: atomic number
Explanation: trust me
Answer:
any characteristic of matter that can be observed without changing the identity of the material. Scientists call a characteristic of matter that you can detect with your senses a Physical property. color, shape, smell, taste, mass, volume, and density.
Explanation: