Answer:
Ft = 0[N]
Explanation:
To understand this problem we must perform an analysis of forces on the X axis, which coincides with the axis of forces of dogs.
In this way performing a sum of forces on the X-axis we will have (newton's third law):
From this analysis we can see that the resulting or total force is equal to zero, since there is no movement.
To solve this problem it is necessary to apply Boyle's law in which it is specified that
Where,
and
are the initial pressure and volume values
and
are the final pressure volume values
The final pressure here is the atmosphere, then
Pressure at the water is given by,
Using Boyle equation we have,
Therefore the volume of the lungs at the surface is 5.9L
a) Increase
b) Unchanged
c) Increase
Explanation:
a)
The charge on a capacitor charging in a RC circuit connected to a battery follows the exponential equation:
where
is the final charge stored in the capacitor, where C is the capacitance and V is the voltage of the battery
t is the time
R is the resistance of the circuit
The capacitor reaches 90% of its final charge when
Substituting and re-arranging the equation, we find:
We see that if we double the RC constant, then
So the time taken will double as well:
So, the answer is "increase"
b)
In this second part, the battery voltage is doubled.
According to the equation written in part a),
this means also that the final charge stored on the capacitor will also double.
However, the equation that gives us the time needed for the capacitor to reach 90% of its full charge is
We see that this equation does not depend at all on the voltage of the battery.
Therefore, if the battery voltage is doubled, the final charge on the capacitor will double as well, but the time needed for the capacitor to reach 90% of its charge will not change.
So the correct answer is
"unchanged"
c)
In this case, a second resistor is added in series with the original resistor of the circuit.
We know that for two resistors in series, the total resistance of the circuit is given by the sum of the individual resistances:
Since each resistance is a positive value, this means that as we add new resistors, the total resistance of the circuit increases.
Therefore in this problem, if we add a resistor in series to the original circuit, this means that the total resistance of the circuit will increase.
The time taken for the capacitor to reach 90% of its final charge is still
As we can see, this time is directly proportional to the resistance of the circuit, R: therefore, if we add a resistor in series, the resistance of the circuit will increase, and therefore this time will increase as well.
So the correct answer is
"increase"
Answer:
Distance, d = 99990 meters
Explanation:
It is given that,
Speed of the train, v = 200 km/h = 55.55 m/s
Time taken, t = 1800 s
Let d is the distance covered by the train. We know that the speed of an object is given by total distance covered divided by total time taken. Mathematically, it is given by :
d = 99990 m
So, the distance covered by the train is 99990 meters. Hence, this is the required solution.