Answer:
option (D)
Explanation:
Here initial rotation speed is given, final rotation speed is given and asking for time.
If we use
A) θ=θ0+ω0t+(1/2)αt2
For this equation, we don't have any information about the value of angular displacement and angular acceleration, so it is not useful.
B) ω=ω0+αt
For this equation, we don't have any information about angular acceleration, so it is not useful.
C) ω2=ω02+2α(θ−θ0)
In this equation, time is not included, so it is not useful.
D) So, more information is needed.
Thus, option (D) is true.
Answer:
4.6 years
Explanation:
This is solved using Kepler's third law which says:

Where
T = Orbital period of the planet (in seconds)
a = Distance from the star (in meters)
G = Gravitational constant
M = Mass of the parent star (in kg)
From the information given



We put this into Kepler's law and get:

This when converted to years is 4.6 years.
Answer:
Flint glass is combination of silicon dioxide (SiO2) with lead or potassium. It creates a relatively high refractive index and high degree of light dispersing power compared to other types of glass.
Explanation:
:)
Answer:
Assuming there are 28 days in each month,
750W = 0.75kW
Cost of electric bill = 0.75 × 8 × 28 × $0.23
= $38.64
Ultraviolet rays can help us get vitamin D, but they can also damage or skin if w are exposed for too long.
Your answer is D.