How does the force exerted by two magnets change as the magnets are moved farther apart?
1 answer:
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Answer:
<em>a. 0.33 Amp</em>
<em>b. 2.4 Volt</em>
<em>c. 0</em>
<em>d. 2.45 Amp</em>
<em>e. Infinite</em>
<em>f. Series is safer</em>
Explanation:
<u>Series Connection of Resistors</u>
When two or more resistors are connected in series, the current through each one of them is the same, and the voltage divides depending on the particular value of each resistance. If all the resistances are equal, then the voltage is equally divided.
a. The string of 50 bulbs is connected to a 120 VAC outlet and consumes 40 W. The power of a circuit is given by
Solving for I
Since all the bulbs are connected in series the current is the same for all of them.
b. The voltage is equally divided, so each bulb has 120/50= 2.4 V
c. If one of the bulbs burns out and its resistance becomes infinite, then the series circuit is open and no current flows through it, neither through the rest of the bulbs. The typical case of the whole string going out.
d. If one of the bulbs short circuits, the resistance of that bulb is zero and the voltage is distributed by the 49 remaining bulbs. Thus the new current is
e. If the bulbs were connected in parallel, all of them would have the same voltage, and the total current will be equally divided among them. In that case, a short circuit in one of the bulbs will cause a parallel short, theoretically producing an infinite current and making the short circuit protection blow up.
f. The condition described above makes the strings be made of series-connected bulbs which is safer than the parallel circuit. If a single bulb shorts, the entire string goes out in a series connection, but the breaker would trigger disconnection of the house circuit if it's a parallel connection. That is why we must deal with unusable strings instead of burning cables.
a) Vertical velocity: 5.9 m/s
b) Horizontal velocity: 5 m/s
Explanation:
a)
The motion of the ball is the motion of a projectile, which consists of two independent motions:
- A uniform motion (constant velocity) along the horizontal direction)
- A uniformly accelerated motion (constant acceleration) along the vertical direction
Here we want to find the vertical component of the ball's velocity. This can be done by using the suvat equation for the vertical motion:
where:
is the vertical velocity at time t
is the initial vertical velocity (zero because the ball has been thrown horizontally)
is the acceleration of gravity (here we take downward as positive direction)
Substituting t = 0.6 s, which is the total time of flight, we find the vertical velocity of the ball just before it hits the ground:
b)
The motion along the vertical direction is an accelerated motion, because there is a force (the force of gravity) acting on the ball and that it causes an acceleration in the ball.
However, there are no forces acting in the horizontal direction on the ball (if we neglect the air resistance): this means that the acceleration of the ball in the horizontal direction is zero.
As a consequence, this also means that the horizontal component of the ball's velocity is constant during the motion.
Since the ball was thrown from the table with an initial horizontal velocity of 5 m/s, this means that the horizontal velocity of the ball just before it hits the floor is still