To solve this problem it is necessary to apply the concepts of Work. Work is understood as the force applied to travel a determined distance, in this case the height. The force in turn can be expressed by Newton's second law as the ratio between mass and gravity, as well

Where,
m = mass
h = height
g = Gravitational constant
When it ascends to the second floor it has traveled the energy necessary to climb a height, under this logic, until the 4 floor has traveled 3 times the height h of each of the floors therefore

Replacing in our equation we have to

The correct answer is 4.
Answer:
(a) Angular velocity will be 125.6 rad/sec
(b) Linear velocity will be 144.44 m /sec
(c) Centripetal acceleration = 1849.3031 g
Explanation:
We have given diameter d = 2.30 m
So radius r = 
(a) Speed is given as 1200 rev/min
We know that angular velocity is given by 
(b) Linear speed is given by 
(c) Centripetal acceleration is given by
We know that 
So 
Answer:
a. Light pollution refers to light used for human activities that brightens the sky and hinders astronomical observations.
Explanation:
Light pollution is due to the excessive and misdirected use of artificial light. Light bulbs are often design in an incorrect way, since a great part of its light is not completely directed to the ground and an important percentage is emitted to the sky in where will be scattered and reflected back to ground by the particles in the atmosphere. That brings as an effect a sky glow, therefore the visibility of astronomical objects will be extremely reduce.
Hence, professional astronomical research and amateur observations will be affected. Light pollution has a negative impact on bird migration at night and in the health of difference species, humans also.
Answer:
Δy = 6.05 mm
Explanation:
The double slit phenomenon is described by the expression
d sin θ = m λ constructive interference
d sin θ = (m + ½) λ destructive interference
m = 0,±1, ±2, ...
As they tell us that they measure the dark stripes, we are in a case of destructive interference, let's use trigonometry to find the sins tea
tan θ = y / x
y = x tan θ
In the interference experiments the measured angle is very small so we can approximate the tangent
tan θ = sin θ / cos θ
cos θ = 1
tan θ = sin θ
y = x sin θ
We substitute in the destructive interference equation
d (y / x) = (m + ½) λ
y = (m + ½) λ x / d
The first dark strip occurs for m = 0 and the third dark strip for m = 2. Let's find the distance for these and subtract it
m = 0
y₀ = (0+ ½) 480 10⁻⁹ 1.7 / 0.27 10⁻³
y₀ = 1.511 10⁻³ m
m = 2
y₂ = (2 + ½) 480 10⁻⁹ 1.7 / 0.27 10⁻³
y₂ = 7.556 10⁻³ m
The separation between these strips is Δy
Δy = y₂-y₀
Δy = (7.556 - 1.511) 10⁻³
Δy = 6.045 10⁻³ m
Δy = 6.05 mm