It is the time period where the commonly accepted theory of the earth being at the center of the solar system is switching over to the refused theory of the sun being at the center of the solar system.
Answer:
U = 2,195 10⁵ J
Explanation:
The potential energy is
U = m g and
in this case each person has a mass of 75 kg and the elevator has a mass of 500 kg, the total mass is
m_total = m_elevator + 4 m_person
m_total = 500 + 4 75
m_toal = 800 kg
let's calculate
U = 800 9.8 28
U = 2,195 10⁵ J
I believe it's a great square
Is b= acid + base - water + salt.
Answer: Nitrogen gas
Explanation:
Using ideal Gas's law
PV = nRT
where
Pressure of gas, P= 1atm
Volume of gas, V= 5.1L
no of moles of gas, n=
Ideal gas constant, R= 0.0821
Temperature of gas, T= 20°C = 20+273 = 293K
also, n= (mass/molar mass)
mass of the gas m = 5.9g
Molar mass of the gas = ?
So, PV = (mRT/M)
We're looking for molar mass M, then
M = mRT/PV
M = (5.9 * 0.0821 * 293)/(1 * 5.1)
M = 141.93/5.1
M = 27.8g/mol ~ 28g/mol
Since the gas is diatomic, then we say,
Atomic mass of gas = 1/2 * molar mass
Atomic mass = 1/2 * 28
Atomic mass = 14
Therefore, the gas is nitrogen.