Answer:
2 secs; 65 feet
Explanation:
The function guiding the water bottle is given as:
f(x) = -16t² + 64t + 1
The bottle will reach maximum height when velocity, df/dt (velocity is the first derivative of distance) = 0.
Therefore:
df/dt = 0 = -32t + 64
=> 32t = 64
t = 64/32 = 2 seconds
This is the time it will take to reach the maximum height.
To find this height, we insert t = 2 into the function f(x):
f = -16(2)² + 64(2) + 1
f = -(16 * 4) + 128 + 1
f = -64 + 128 + 1
f = 65 ft
Its maximum height is 65 ft.
Answer:
I THINK it's A but I'm not completely sure
Explanation:
It is given that,
Wavelength of red light, 
Power of the laser, 
(a) The energy carried by each photon is given by :


(b) Let n is the number of photons emitted by the laser per second. It can be calculated as :


Hence, this is the required solution.
Answer:
D. n=6 to n=2
Explanation:
Given;
energy of emitted photon, E = 3.02 electron volts
The energy levels of a Hydrogen atom is given as; E = -E₀ /n²
where;
E₀ is the energy level of an electron in ground state = -13.6 eV
n is the energy level
From the equation above make n, the subject of the formula;
n² = -E₀ / E
n² = 13.6 eV / 3.02 eV
n² = 4.5
n = √4.5
n = 2
When electron moves from higher energy level to a lower energy level it emits photons;

For a photon to be emitted, electron must move from higher energy level to a lower energy level. The higher energy level is 6 while the lower energy level is 2
Therefore, The electron energy-level transition is from n = 6 to n = 2
Answer:
True
Explanation:
The tensile stress, σ, on a solid cylindrical wire is given by the following relationship;

Where;
= The tensile force
= The original cross sectional area of the cylindrical wire = π·R²
R = The radius of the wire
Therefore;
= σ ×
= σ × π × R²
Therefore, the tensile force is directly proportional to the square of the radius of the cylindrical wire, and as the radius of the wire increases, which is by increasing the thickness of the wire, the tensile force is largely increased
The correct option is; True.