Answer:
A. chemical substance whose atoms all have the same number of protons
Explanation:
An element is a substance which contains identical atoms that have the same number of protons in the nucleus.
Elements are arranged in the periodic table according to their atomic number (= number of protons): so atoms of different elements have a different number of protons in their nuclei.
For a neutral atom, the number of electrons around the nucleus is also equal to the number of protons.
Moreover, atoms of the same element can have a different number of neutrons, despite having the same number of protons - these atoms are called isotopes.
First we have to calculate the time taken to travel the distance 30 m, is
.
Now from equation of motion,
Given, 
.
As object starts from rest, so u = 0.
Substituting these values in above equation, we get
.
Thus, the acceleration is 
Answer:
342 m/s
Explanation:
The velocity of sound in air is approximated as:
v ≈ 331.4 + 0.6 T
where v is the velocity in m/s and T is the temperature in Celsius.
At T = 18:
v ≈ 331.4 + 0.6 (18)
v ≈ 342.2
The velocity is approximately 342 m/s.
Answer:
i do belive its C
Explanation:
i remeber this question from somewhere also it makes the most sense
Answer:
Mass = 386 kg
Explanation:
<u><em>Density = Mass / Volume</em></u>
Mass = Density × Volume
Where D = 19300 kg/m³ , V = 0.02 m³
<em>Putting the given in the above formula</em>
Mass = 19300 × 0.02
Mass = 386 kg
