Answer:
The average speed of the elevator going down in the abandoned mine is 17.722mph.
Explanation:
If the elevator takes 90 seconds to descend a height of 713m, the average speed of the elevator is:

And if 1m/s is 2.23694mph, the average speed is:
.
Answer:
λ = 65.6 pm
Explanation:
Given that
λo = 65 pm
The initial energy of the electron

Now by putting the values




Eo=19.06 KeV
Given that kinetic energy KE= 0.84 KeV
Therefore the final energy
E= Eo - KE
E = 19.06 - 0.84 KeV
E= 18.22 KeV
The wavelength λ can be find as



λ = 6.56 x 10⁻¹¹ m
λ = 65.6 pm
Since the greatest number in the given electron configuration of the atom is 4, it means that the element is found in the fourth energy level. The number of electrons found in the valence shell is 2+10+6 = 18. From this answer and using the periodic table, we can see that the atom is that of Krypton (Kr).
Answer:
Acceleration of the boy a₁:

Explanation:
Conceptual analysis
We apply Newton's second law to the boy and the girl:
F = m*a (Formula 1)
F : Force in Newtons (N)
m : mass in kilograms (kg)
a : acceleration in meters over second square (m/s²)
Nomenclature
m₁ : boy mass
m₂ : girl mass
a₁ : boy acceleration
a₂ : girl acceleration
F₁ : boy acceleration
F₂ : girl acceleration
Known data
m₁ = 57 kg
m₂ = 41 kg
a₂ = 2.6 m/s²
Problem development
We apply to Newton's third law of action and reaction, then:
F₁ = F₂ , We apply the formula (1):
m₁*a₁ = m₂*a₂



Answer:
The inductance of this solenoid is 5.51 mH.
Explanation:
Given that,
length of the tube, l = 38 cm = 0.38 m
Diameter of the tube, d = 8.3 cm
Radius of the tube, r = 4.15 cm
The number of turns, N = 555
We need to find the inductance of this solenoid. It is given by the formula as :

So, the inductance of this solenoid is 5.51 mH. Hence, this is the required solution.