We know that the measure of an incident ray is: α 1 = 40°.
The index of refraction:
- for the air : n 1 = 1.00,
- for the water: n 2 = 1.33
Snell`s Law of Refraction :
n 1 · sin α 1 = n 2 · sin α 2
sin α 2 = n 1 · sin α 1 / n 2 =
= 1.00 · sin 40° / 1.33 = 0.64278 / 1.33 = 0.4833
α 2 = sin ^(-1) 0.4833
α 2 = 28.9 °
Answer: The angle relative to the water`s surface of the rays when beneath the surface is 28.9°.
Answer:v=2 m/s
Explanation:
Given
Length of string L=1.2 m
mass of pendulum m=0.25 kg
maximum inclination with vertical \theta =34
vertical Rise of Pendulum from its mean position is given by

Conserving Energy at top and bottom point
Potential Energy of sphere is converted into kinetic energy of sphere





Answer:
0.83 ω
Explanation:
mass of flywheel, m = M
initial angular velocity of the flywheel, ω = ωo
mass of another flywheel, m' = M/5
radius of both the flywheels = R
let the final angular velocity of the system is ω'
Moment of inertia of the first flywheel , I = 0.5 MR²
Moment of inertia of the second flywheel, I' = 0.5 x M/5 x R² = 0.1 MR²
use the conservation of angular momentum as no external torque is applied on the system.
I x ω = ( I + I') x ω'
0.5 x MR² x ωo = (0.5 MR² + 0.1 MR²) x ω'
0.5 x MR² x ωo = 0.6 MR² x ω'
ω' = 0.83 ω
Thus, the final angular velocity of the system of flywheels is 0.83 ω.
Answer:
R=19.5m
= 4.65° S of W
Explanation:
Refer the attached fig.
displacement of the x and y components
x-component displacement is (
) = 
= A
(20°) + B
(40°)
= -12.0
(20°) + 20.0
(40°)
= -19.425m
x-component displacement is (
) = 
= A
(20°) - B
(40°)
= 12.0
(20°) - 20.0
(40°)
= -1.579
resultant displacement
∴
R = 
=
=19.5m
= 
= 
= 4.65° S of W
The heat released by the water when it cools down by a temperature difference

is

where
m=432 g is the mass of the water

is the specific heat capacity of water

is the decrease of temperature of the water
Plugging the numbers into the equation, we find

and this is the amount of heat released by the water.