Answer:
1) a block going down a slope
2) a) W = ΔU + ΔK + ΔE, b) W = ΔE, c) W = ΔK, d) ΔU = ΔK
Explanation:
In this exercise you are asked to give an example of various types of systems
1) a system where work is transformed into internal energy is a system with friction, for example a block going down a slope in this case work is done during the descent, which is transformed in part kinetic energy, in part power energy and partly internal energy that is represented by an increase in the temperature of the block.
2)
a) rolling a ball uphill
In this case we have an increase in potential energy, if there is a change in speed, the kinetic energy also increases, if the change in speed is zero, there is no change in kinetic energy and there is a change in internal energy due to the stationary rec in the point of contact
W = ΔU + ΔK + ΔE
b) in this system work is transformed into internal energy
W = ΔE
c) There is no friction here, therefore the work is transformed into kinetic energy
W = ΔK
d) if you assume that there is no friction with the air, the potential energy is transformed into kinetic energy
ΔU = ΔK
<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>
Answer:
<u>Assuming b = 9.3i + 9.5j</u> <em>(b = 931 + 9.5 is wrong):</em>
a) a×b = 34.27k
b) a·b = 128.43
c) (a + b)·b = 305.17
d) The component of a along the direction of b = 9.66
Explanation:
<u>Assuming b = 9.3i + 9.5j</u> <em>(b = 931 + 9.5 is wrong)</em> we can proceed as follows:
a) The vectorial product, a×b is:

b) The escalar product a·b is:

c) <u>Asumming (a</u><u> </u><u>+ b)·b</u> <em>instead a+b·b</em> we have:
![(a + b)\cdot b = [(8.6 + 9.3)i + (5.1 + 9.5)j]\cdot (9.3i + 9.5j) = (17.9i + 14.6j)\cdot (9.3i + 9.5j) = 305.17](https://tex.z-dn.net/?f=%28a%20%2B%20b%29%5Ccdot%20b%20%3D%20%5B%288.6%20%2B%209.3%29i%20%2B%20%285.1%20%2B%209.5%29j%5D%5Ccdot%20%289.3i%20%2B%209.5j%29%20%3D%20%2817.9i%20%2B%2014.6j%29%5Ccdot%20%289.3i%20%2B%209.5j%29%20%3D%20305.17)
d) The component of a along the direction of b is:

I hope it helps you!
Answer:
The angle formed of the rope with the surface = 40°
Force applied = 125Newtons
The displacement covered by the box =25metres
W= FDcos theta
[125×40×cos(40°) ] Joules
= [ (3125×0.76604444311)]Joules
= 2393.88888472 joules(ans)
Hope it helps
Answer:
The line charge density is 
Explanation:
Given that,
Diameter = 2.54 cm
Distance = 19.6 m
Potential difference = 115 kV
We need to calculate the line charge density
Using formula of potential difference



Where, r = radius
V = potential difference
Put the value into the formula


Hence, The line charge density is 