During upward projection the final velocity is zero, and the gravitational acceleration is -10 m/s² (against the gravity).
Therefore; using the equation;
S = 1/2gt² + ut
Where s is the height h, g is gravitational acceleration, and t is the time and u is the initial velocity u, is 16 ft/s.
Thus; h= 1/2(-10)t² + 16t
We get; h = -5t² + 16t
Therefore; the quadratic equation is 5t² - 16t + h =0
This is a "trick" question.
If the elevator is traveling at constant speed, it means it is at rest. This means anything inside the elevator traveling at constant speed, weights the same as in an elevator not moving -also at rest-.
So the 100N weight's weight doesn't change in an elevator traveling at constant speed.
Answer- Helium
You can by the number of protons, and if you look at a periodic table the atomic number of helium is the same as the number of protons
If you know an element’s atomic number, you will learn the number of protons and electrons. The atomic number is equal to the number or protons and electrons. You can also find the number of neutrons, by subtracting the atomic mass from the atomic number.
For example, Fluorine’s atomic number is 9, and its atomic mass is 19. So, the number of electrons and protons in fluorine is 9. The number of neutrons the is equal to 19-9. Thus, Fluorine has 10 neutrons.
Hope this helps :)
