<span>The correct answer is C) a motor.
In particular, we are talking about an AC motor, which produces an alternating current. In an AC motor, a coil is immersed in a rotating magnetic field. Due to the motion of the magnetic field,the angle between the direction of the field and the surface enclosed by the coil changes. As a result, the magnetic flux through the coil changes over time (the magnetic flux is given by:
</span>

<span>
where B is the intensity of the magnetic field, A is the area enclosed by the coil and </span>

<span> is the angle between the direction of B and the perpendicular to the plane of the coil). For Faraday-Newmann-Lenz law, this change in flux induces an electromotive force (emf) into the coil, according to:
</span>

<span>
where the numerator is the variation of magnetic flux and dt is the time interval. This emf in the coil produced an electrical current in the circuit.</span>
Answer:
t = 4.21x10⁻⁷ s
Explanation:
The time (t) can be found using the angular velocity (ω):
<em>Where θ: is the angular displacement = π (since it moves halfway through a complete circle)</em>
We have:
<u>Where</u>:
<em>v: is the tangential speed </em>
<em>r: is the radius</em>
The radius can be found equaling the magnetic force with the centripetal force:

Where:
m: is the mass of the alpha particle = 6.64x10⁻²⁷ kg
q: is the charge of the alpha particle = 2*p (proton) = 2*1.6x10⁻¹⁹C
B: is the magnetic field = 0.155 T
Hence, the time is:

Therefore, the time that takes for an alpha particle to move halfway through a complete circle is 4.21x10⁻⁷ s.
I hope it helps you!
Answer:

Explanation:
Let the distance moved by Joe is "d"
so the time taken by him to drove it by speed 45 mph is given as


now the same distance is traveled by him with speed 55 mph
so the time taken by him

so total time taken by him for complete distance 2d



now the average speed is given as



Burning of gases is one the example of chemical change
Answer:
1531 m
Explanation:
The motion of the jet ski is an uniformly accelerated motion, so we can find the distance travelled by using the following suvat equation:

where
s is the distance
u is the initial velocity
t is the time
a is the acceleration
For the jet ski in this problem,

t = 35 s
u = 0 (it starts from rest)
Solving for s, we find the distance travelled:
