Let
V the speed of the girl per step
v the speed of the escalator per step
L the length between ground and floor in number of steps
V*60+v*60=L => V+v=L/60
V*90-v*90=L => V-v=L/90
By adding the equations V+v=L/60 and V-v=L/90 we get:
2V=L(3+2)/180
V=5L/360
V = L/72
Time to climb (in steps) with v=0 (escalator standing still) is:
V*t=L
t = L/V
t = L/(L/72)
t =72 steps
The girl will count 72 steps.
with a -1 iron charge it becomes an electrode
Answer:
Hindi ko alam pasensya ka ha godbless
<u>Question:
</u>
The law of conservation of mass follows from the concept that a. atoms are indivisible. b. atoms of different elements have different properties. c. matter is composed of atoms. d. atoms can be destroyed in chemical reactions.
<u>Answer:</u>
The law of conservation of mass follows from the concept that atoms are indivisible
<u>Explanation:
</u>
The law of conservation of mass tells that atoms in an object neither can be created nor be destroyed, but they can be transferred around and transformed into various particles. Also, it says that the total mass preceding the chemical reaction corresponds to the total mass after the chemical reaction.
In other words, the mass remains intact. Lavoisier formulated this law as a result of a combustion experiment in which he stated that the weight of his starting material - a glass jar, tin and air - was equal to the mass of the material produced - a glass jar, "Tin calcium" and the rest of the air.
The term "atom" arrives from the language of Greek and means indivisible, because atoms were thought to be the tiny things present in the universe and could not be divided. But not familiar that atom comprises with three particles: proton, neutron and electron- even tiny particles like quarks.
