<span>Match the basic components of a nuclear reactor with their descriptions.
1. slows down neutrons
moderator - This is the substance that slows down fast neutrons and makes them slow neutrons which are easier to capture by the atomic nuclei so that the fission reaction can continue.
2. absorb emitted neutrons
control rods - These are rods made up of a substance that easily absorbs neutrons. Their purpose is to slow down or shut down the reaction.
3. mass of unstable atoms
nuclear fuel - The entire point of a nuclear reactor is the capture the energy released by the fission of unstable atoms. So this mass of unstable atoms is the fuel for the nuclear reactor.
4. concrete and lead enclosure
shield - This is the enclosure that prevents radiation from escaping into the general environment.
5. energy transfer medium
coolant - Since the purpose of a nuclear reactor is to generate usable energy, the coolant extracts heat from the fissioning core and that heat is generally used to boil water which in turn is used to operate turbines that power electrical generators.</span>
Continuing in an existing state. Resistance to change.
Sound level at distance of 15 m is given as 20 dB
so intensity at this distance is given as
now if we move closer to some some distance the sound level is now 50 dB
now the intensity is given as
now we know that
so now the distance from friend must be 47 cm
Decreasing the trains velocity will DECREASE the kinetic energy
Answer:
Explanation:
Remark
At the time it takes to drop 20 m is the same time it takes to travel 60 m horizontally.
Givens
h = 20 m
hd = 60 m
g = 9.81
vi = 0
Formula
d = vi*t + 1/2 a * t^2 We are solving for t
Solution
When the battery fails, the vertical initial velocity is 0. So we have to find the time it would take to drop 20 meters
d = 0*t + 1/2 * 9.81 a* t^2
20 = 4.91 * t^2 Divide by 4.91
20/4.91 = 4.91 t^2 / 4.91
4.073 = t^2 Take the square root of both sides.
t = 2.02 seconds
Horizontal
d = 60 m
t = 2.02 seconds
v = ?
Note: there is no horizontal deceleration or acceleration
v = d/t
v = 60/2.02
Answer: v = 29.73 m/s
