Solution: The correct order is: C, A, B
The statement of the problem:
How can we prove Earth is round and calculate its circumference?
Hypotheis:
If the sun casts shadows at different angles at the same time of day in different places, we can determine how much Earth curves.
If the Earth was flat, the angle measured at different places at the same time of the day would be same.
Observation:
In Syene, the sun's rays are vertical at noon. At the same time in Alexandria, the rays are 7.2 degrees from the vertical.
Momentum is a protector the mass and the velocity of a moving object.
Momentum= mass*speed
For Car A: Mass:1,000 kilograms Velocity: 40 meters/second;
Momentum=1,000 kg*40 m/s
=40000kg.m/s
For Car B: Mass: 4,000 kilograms Velocity 10 meters/second;
Momentum=4000kg*10m/s
=40000kg.m/s
Both cars require the same amount of force to stop. This is because they have the same momentum.
Answer:
a) n = 9.9 b) E₁₀ = 19.25 eV
Explanation:
Solving the Scrodinger equation for the electronegative box we get
Eₙ = (h² / 8m L²2) n²
where l is the distance L = 1.40 nm = 1.40 10⁻⁹ m and n the quantum number
In this case En = 19 eV let us reduce to the SI system
En = 19 eV (1.6 10⁻¹⁹ J / 1 eV) = 30.4 10⁻¹⁹ J
n = √ (In 8 m L² / h²)
let's calculate
n = √ (8 9.1 10⁻³¹ (1.4 10⁻⁹)² 30.4 10⁻¹⁹ / (6.63 10⁻³⁴)²
n = √ (98) n = 9.9
since n must be an integer, we approximate them to 10
b) We substitute for the calculation of energy
In = (h² / 8mL2² n²
In = (6.63 10⁻³⁴) 2 / (8 9.1 10⁻³¹ (1.4 10⁻⁹)² 10²
E₁₀ = 3.08 10⁻¹⁸ J
we reduce eV
E₁₀ = 3.08 10⁻¹⁸ j (1ev / 1.6 10⁻¹⁹J)
E₁₀ = 1.925 101 eV
E₁₀ = 19.25 eV
the result with significant figures is
E₁₀ = 19.25 eV