Answer:
e. TA>T>Tc
Explanation:
a) In this case, we cannot say for sure QA>QB>QC. This is because the magnitude of the heat flow will depend on the specific heat and the mass of each sample. Due to the equation:

if we did an energy balance of the system, we would get that>
QA+QB+QC=0
For this equation to be true, at least one of the heats must be negative. And one of the heats must be positive.
We don't know either of them, so we cannot determine if this statement is true.
b) We can say for sure that QA<0, because when the two samples get to equilibrum, the temperatrue of A must be smaller than its original temperature. Therefore, it must have lost heat. But we cannot say for sure if QB<0 because sample B could have gained or lost heat during the process, this will depend on the equilibrium temperature, which we don't know. So we cannot say for sure this option is correct.
c) In this case we don't know for sure if the equilibrium temperature will be greater or smaller than TB. This will depend on the mass and specific heat of the samples, just line in part a.
d) is not complete
e) We know for sure that A must have lost heat, so its equilibrium temperature must be smaller than it's original temperature. We know that C must have gained heat, therefore it's equilibrium temperature must be greater than it's original temperature, so TA>T>Tc must be true.
Answer:
A )
Explanation:
This change in frequency observation occur due to doppler effect
if the wave source moves,In the time between one wave peak being emitted and the next, the source will have moved so that the shells will no longer be concentric. The wavefronts will get closer together in front of the source as it travels and will be further apart behind it. (see the graph)
when the person standing still in front of the ambulance, he will observe a <em>higher frequency </em>than before as the source travels towards them.

The pitch we hear depends on the frequency of the sound wave.
A high frequency corresponds to a high pitch
as we hear a higher frequency , it makes the <em>pitch higher</em> too
A short circuit is said to have occurred when two nodes of a circuit at different voltages are abnormally connected
There is said to be a short circuit when; <u>One part of a parallel circuit has a very low resistance and almost all the current will flow through this part and very little current will flow through the other part</u>
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The correct option is option B.
Reason:
A circuit has to be closed or the the current path has to be closed for
current to flow. A short circuit occurs when current in a circuit flows
through an abnormal path, such as a bridge in a connection to a load that
creates a parallel path for current flow.
Almost all the current flows through the parallel path due to the low
resistance in the connection (almost zero) and the proximity to the power
source, thereby preventing current from reaching its intended destination
Therefore, the correct option is option B.;
Learn more here:
brainly.com/question/23779827
brainly.com/question/19912277
Answer:

Explanation:
Mass: M, Length: L.

The formula that gives center of mass is

In the case of a non-uniform mass density, this formula converts to

where the denominator is the total mass and the nominator is the mass times position of each point on the rod.
We have to integrate the mass density over the total rod in order to find the total mass. Likewise, we have to integrate the center of mass of each point (xσ(x)) over the total rod. And if we divide the integrated center of mass to the total mass, we find the center of mass of the rod:

Here x's are cancelled. Otherwise, the denominator would be zero.

Answer:
Beta particle
Explanation:
If an alpha particle and a beta particle have the same energy, beta particle will penetrate farther into an object than alpha particle because;
1. In air, beta particles can travel a few hundred times farther than alpha particles.
2. Beta particles have more penetrating power than alpha particles.
3. Alpha particle can be absorbed or stopped by an inch or less 1-2 centimeters of air or a thin piece of tissue while beta particles can be stopped or absorbed by a thin layer of Aluminium.
4. Alpha particles loose all of their energies in a small volume easily that beta particles.
5. Beta particles can traveled a longer distance between 2-3 meters at a speed nearly equal to that of light than alpha particles which travel a distance between 2-4 cm at a speed approximately five percent the speed of light.