Students in physical education class must ____

You need to design a 60.0-Hz ac generator that has a maximum emf of 5200 V. The generator is to contain a 180-turn coil that has

OlgaM077 [116]

Answer:

0.082 T

Explanation:

Given:

Frequency of the generator (f) = 60.0 Hz

Maximum emf of the generator (E) = 5200 V

Number of turns (N) = 180

Area per turn (A) = 0.94 m²

Magnetic field magnitude (B) = ?

We know that, the angular frequency of the generator is given as:

$\omega=2\pi f$

Plug in the value of 'f' and solve for 'ω'. This gives,

$\omega=2\pi\times 60.0=120\pi\ rad/s$

Now, the maximum emf of the generator is given by the formula:

$E=NAB\omega$

Rewriting in terms of magnetic field, 'B', we get:

$B=\frac{E}{NA \omega}$

Plug in the given values and solve for 'B'. This gives,

$B=\frac{5200\ V}{180\times 0.94\ m^2\times 120\pi\ rad/s}\\\\B=\frac{5200\ V}{63786.897}\\\\B=0.082\ T$

Therefore, the magnitude of the magnetic field in which the coil rotates is 0.082 T.

8 0

4 years ago

Tina and her puppy are tugging on a rope, each pulling on opposite ends.

anyanavicka [17]

Work is done when the ‘object moves in the same direction as the force’ an example being a man walking up a flight of stairs carrying a box of weight.

Work is not done when the direction of the applied force and the direction in which the object moves are PERPENDICULAR to each other. An example being A man carrying a load while walking, no work is done on the load in the upward direction as the load is only moving horizontally.

Thus the answer is whenever she pulls the puppy towards her

3 0

3 years ago

During a workout, a football player pushes a blocking dummy a distance of 30 m. While pushing the dummy the same distance a seco

Pavel [41]

Explanation:

Power = work / time

Work = force × distance

Therefore:

Power = force × distance / time

Since the distance is the same, he would have to either increase the force he exerts or decrease the time (increase his velocity) in order to increase the amount of work done.

5 0

3 years ago

A car is moving at constant velocity +48.8 m/s along a straight highway. Suddenly the driver spots a stalled vehicle 378.7 m ahe

Katen [24]

Answer:

a = - 3.14[m/s^2]

Explanation:

To solve this problem we must use the following kinematic equation:

$v_{f} ^{2}= v_{o} ^{2}+2*a*dx\\where:\\v_{f} = final velocity = 0 [m/s]\\v_{o}= initial velocity = 48.8 [m/s]\\ a = acceleration [m/s^2]\\dx = displacement [m]\\$

Now replacing:

$0 = 48.8^{2}+2*a*(378.7) \\-2381.44 = 757.4*a\\a = -3.14[m/s^2]$

The negative sign means the vehicle slows down.

4 0

4 years ago

Earth's rotational axis completes one precession every _____.

ruslelena [56]

A). Earth completes one rotation on its rotation axis
every (3 minutes and 56 seconds less than 24 hours).
This causes night and day. It's rotation, not precession.

B). Earth completes one orbital revolution around the sun
every (365 plus a little bit) days. It's revolution, not precession.

C). I'm not sure what happens on a cycle of 512 years.
It may have something to do with the moon. But whatever
it is, it's not precession.

D). When you spin a top and it starts to run down, the first
thing that happens is that the handle of the top, or the point
on top of the top, starts moving in a circle. That's precession.
That's what the Earth's axis is doing. The north pole points
toward the north star (Polaris) now. But the north pole is
actually drawing out a big circle in the sky, and other stars
will become the "north star" far in the future.
The north pole draws out a full circle in the sky, roughly
once every 26,000 years. That's precession.

6 0

4 years ago

Students in physical education class must _____?