Water is initially present in a state where its molecules are far apart. During a change of state, its molecules slow down. Whic
2 answers:
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(Missing question is: which of the following statements are true?)
a) <span>A battery does work on electric charges to bring them to a position of higher electric potential energy so that they can flow through a circuit to a lower potential energy --> TRUE
That's true: the battery does the work to move the charges to one end of its terminal thus creating a potential difference between the two terminals. Then, when it is connected to the circuit, charges start to flow to the terminal at lower potential (through the circuit)
b) </span><span>the potential difference between the terminals of a battery, when no current flows to an external circuit, is referred to as the terminal voltage --> FALSE
This is false: when no current flows, it is called e.m.f. (electromotive force)
c) </span><span>the internal resistance of a battery decreases with decreasing temperature
--> TRUE
In fact, the dependence of a resistance with the temperature is:
</span>![R=R_0[1+\alpha (T-T_0)]](https://tex.z-dn.net/?f=R%3DR_0%5B1%2B%5Calpha%20%28T-T_0%29%5D)
with
being generally positive, therefore the value of the resistance is proportional to T, and when T decreases, R decreases as well.
<span>d) a battery is a device that produces electricity by transforming chemical energy into electrical energy --> TRUE
</span><span>That's true: a battery uses chemical reactions to create a potential difference between the two terminals that can be exploited to make charges flowing through a circuit.
</span>
a) <span>A battery does work on electric charges to bring them to a position of higher electric potential energy so that they can flow through a circuit to a lower potential energy --> TRUE
That's true: the battery does the work to move the charges to one end of its terminal thus creating a potential difference between the two terminals. Then, when it is connected to the circuit, charges start to flow to the terminal at lower potential (through the circuit)
b) </span><span>the potential difference between the terminals of a battery, when no current flows to an external circuit, is referred to as the terminal voltage --> FALSE
This is false: when no current flows, it is called e.m.f. (electromotive force)
c) </span><span>the internal resistance of a battery decreases with decreasing temperature
--> TRUE
In fact, the dependence of a resistance with the temperature is:
</span>
with
<span>d) a battery is a device that produces electricity by transforming chemical energy into electrical energy --> TRUE
</span><span>That's true: a battery uses chemical reactions to create a potential difference between the two terminals that can be exploited to make charges flowing through a circuit.
</span>
Answer:
The speed of the top of the wheel is twice the speed of the car.
That is: 72 m/s
Explanation:
To find the speed of the top of the wheel, we need to combine to velocities: the tangential velocity of the rotating wheel due to rotational motion - with
being the wheel's angular velocity,
plus the velocity due to the translation of the center of mass (v = 36 m/s).
The wheel's angular velocity (in radians per second) can be obtained using the tangential velocity for the pure rotational motion and it equals:
Then the addition of these two velocities equals: