Answer:
the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated.
Explanation:
The correct answer is - A. Plants store solar energy; the plants die; the plants are compressed; solar energy is released;
The plants use the solar energy for their functioning, thus they are one of the biggest natural storage of it. The plants also use the CO2 for the process of photosynthesis that is driven by the solar energy. When the plants die, the things inside them are stored in them, and if they are quickly covered they will remain stored and not get back into the atmosphere. The plants than are compressed, and over time that leads to a change in their composition. After millions of years had passed, the solar energy and CO2 had turned into coal. The coal is heavily used by the humans in the past few centuries, and with its burning the solar energy and the CO2 are released back into the atmosphere from which they came millions of years ago.
Answer:
The sun's gravity pulls the planet toward the sun, which changes the straight line of direction into a curve. This keeps the planet moving in an orbit around the sun. Because of the sun's gravitational pull, all the planets in our solar system orbit around it.
Answer:
θ = 4.716 10⁻⁶ rad
Explanation:
In order for the releases to be considered separate, they must meet the Rayleigh criterion that establishes that the maximum diffraction of one star must coincide with the first minimum of the diffraction pattern of the second star.
We use the diffraction equation for a slit
a sin θ = m λ
The minimum occurs at m = 1
sin θ = λ / a
Since the angles in these systems are very small, we can approximate the sine to its angle in radians
θ = λ / a
The telescope has a circular aperture whereby polar cords should be used, which introduces a constant number
θ = 1.22 λ / a
Let's calculate
θ = 1.22 518 10⁻⁹ / 13.4 10⁻²
θ = 4.716 10⁻⁶ rad
Answer:
a) 3.43 m/s
Explanation:
Due to the law of conservation of momentum, the total momentum of the bullet - rifle system must be conserved.
The total momentum before the bullet is shot is zero, because they are both at rest, so:
Instead the total momentum of the system after the shot is:
where:
m = 0.006 kg is the mass of the bullet
M = 1.4 kg is the mass of the rifle
v = 800 m/s is the velocity of the bullet
V is the recoil velocity of the rifle
The total momentum is conserved, therefore we can write:
Which means:
Solving for V, we can find the recoil velocity of the rifle:
where the negative sign indicates that the velocity is opposite to direction of the bullet: so the recoil speed is
a) 3.43 m/s
