Answer:
θ₂ = 35.26°
Explanation:
given,
refractive index of air, n₁ = 1
refractive index of glass, n₂ = 1.5
angle of incidence, θ₁ = 60°
angle of refracted light, θ₂ = ?
using Snell's Law
n₁ sin θ₁ = n₂ sin θ₂
1 x sin 60° = 1.5 sin θ₂
sin θ₂ = 0.577
θ₂ = sin⁻¹(0.577)
θ₂ = 35.26°
Hence, the refracted light is equal to θ₂ = 35.26°
As the distance from the Sun increases the time to orbit the Sun increases. <em>(a)</em>
Examples:
-- Nearest planet to the sun: Mercury. Time to orbit the sun: 88 days
-- 3rd planet from the sun: Earth. Time to orbit the sun: 1 year
-- 5th planet from the sun: Jupiter. Time to orbit the sun: 12 years
-- 9th closest object to the sun: Pluto. Time to orbit the sun: 248 years
Another pair of examples:
-- Object in a near Earth orbit: International Space Station
Time to orbit the Earth: 90 minutes
-- Object in a far Earth orbit: the Moon
Time to orbit the Earth: 27.3 days
The reason for all of this is: Two things about orbits.
1). The larger the orbit is, the farther the object has to travel around it.
2). The farther out the object is, the slower it travels in its orbit.
This is simply the way gravity works.
Fracture is the characteristic way a mineral breaks. The difference between cleavage and fracture is that cleavage is the break of a crystal face where a new crystal face is formed where the mineral broke, whereas fracture is the "chipping" of a mineral making it Uneven - A fracture that leaves a rough or irregular surface.
The body of a porter carrying load on head on a level road uses more energy than is required when the porter is resting completely. In this way the porter is doing some work.
However, when we think of theoretical definition of work, there is no force resisting the horizontal movement of the load when carried on a level road, and therefore there is no work done when a porter carrying a load on his head walk along a level road.
When the porter is going down the stairs the gravitational energy acting on the load is assisting the downward movement of the load. In this way energy is released by downward movement of the load. Thus the porter is doing negative work on the load.
