Answer:
2.63 x 10^18
Explanation:
A = 1 cm^2 = 1 x 10^-4 m^2
λ = 10,000 nm = 10,000 x 10^-9 m = 10^-5 m
T = 37 degree C = 37 + 273 = 310 k
Energy of each photon = h c / λ
where, h is the Plank's constant and c be the velocity of light
Energy of each photon = (6.63 x 10^-34 x 3 x 10^8) / 10^-5 = 1.989 x 10^-20 J
Energy radiated per unit time = σ A T^4
Where, σ is Stefan's constant
Energy radiated per unit time = 5.67 x 10^-8 x 10^-4 x 310^4 = 0.05236 J
Number of photons per second = Energy radiated per unit time / Energy of
each photon
Number of photons per second = 0.05236 / (1.989 x 10^-20) = 2.63 x 10^18
Answer:
Melting
Explanation:
The process of a solid becoming a liquid is called melting. (an older term that you may see sometimes is fusion). The opposite process, a liquid becoming a solid, is called solidification. For any pure substance, the temperature at which melting occurs—known as the melting point—is a characteristic of that substance.
Answer:
I'm not sure..but please refer to your teacher later.
Answer: Based on Newton's First law of motion (where inertia is involved), smooth ice increases the forceused to accelerate the hockey puck.
Explanation;
- smooth ice reduces the resistances between the surface of the figure skates and the ice itself.
- based on inertia theory ; the heavier the weight, the larger the inertia.. which explains it takes alot of force to move a heavier object than the lighter ones.. it also hard to *stop* the motion of heavier objects than the lighter ones.
- now let's look at the design of the player shoe itself, they have a sharp blade at the bottom of the figure stakes.. which takes us to the law of the force.. the smaller the surface area, the more forces acting on it. So, players force (weight, F= mg) acts on the tip of the blade and on the ice
- high inertia (run fast) and high force (attack opponent and pass puck) enables them to perform well in playing hockey
- Thus if there's no resistance and the inertia of the player is high then they could run and pass the puck quickly
Answer: The bond that hold water molecules together are due to shared electrons. The bond of shared electrons is known as a covalent bond.
Explanation: Water is held together by bonds known as covalent bonds, in which electrons are shared by the elements. In this case, the two hydrogen atoms and the one oxygen atom share a bond in which they share electrons, attaining a full outer shell.
The atom must have gained 1 or more electrons or must have lost 1 or more electrons.
