Answer:
The correct answer might be 
meters.
Explanation:
<u>The Answer Given might not be correct, I just did what my brain said.</u>
As the angle is perpendicular so Θ=90.
Putting this in the equation to calculate the magnetic force as:
F = evBsinΘ
F= evBsin90 *sin90 = 1 so,
F= evB.
Now when the electron will start to move in a circle, The necessary force that makes the electron rotate in a circle is given by Centripetal force.
So,
Magneteic Force = Centripetal Force
evB = 
r = 
......(1)
Now the problem is, We don't know " v " so we need to calculate velocity first,
Calculation of Velocity:
In order to calculate the velocity of electron, We should know the potiential difference with which the electrons are accelerated which in our case is 500ev. If "V" is the potiential difference, the energy gained by electrons during accelreation will be Ve. This appear as kinectic enrgy of electrons as,
K.E = Ve
m
= Ve
v = 
................(2)
Putting value of velocity in equation 2 from 1:
r =
meters.
Acceleration is the rate of
change of the velocity of an object that is moving. This value is a result of
all the forces that is acting on an object which is described by Newton's
second law of motion. <span>Calculation of such is
straightforward, if we are given the final velocity, the initial velocity and
the total time interval. We can just use the kinematic equations. Fortunately, we are given these values. So, we calculate as follows:
</span>
acceleration = v - v0 / t
acceleration = (80 mph - 50 mph) ( 1 h / 3600) / 5 s
acceleration = 1.67 x 10^-3 m / s^2
Therefore, the acceleration of the car is 1.67 x 10^-3 m / s.
<span>Since there is no friction, conservation of energy gives change in energy is zero
Change in energy = 0
Change in KE + Change in PE = 0
1/2 x m x (vf^2 - vi^2) + m x g x (hf-hi) = 0
1/2 x (vf^2 - vi^2) + g x (hf-hi) = 0
(vf^2 - vi^2) = 2 x g x (hi - hf)
Since it starts from rest vi = 0
Vf = squareroot of (2 x g x (hi - hf))
For h1, no hf
Vf = squareroot of (2 x g x (hi - hf))
Vf = squareroot of (2 x 9.81 x 30)
Vf = squareroot of 588.6
Vf = 24.26
For h2
Vf = squareroot of (2 x 9.81 x (30 – 12))
Vf = squareroot of (9.81 x 36)
Vf = squareroot of 353.16
Vf = 18.79
For h3
Vf = squareroot of (2 x 9.81 x (30 – 20))
Vf = squareroot of (20 x 9.81)
Vf = 18.79</span>
Answer:
D. The water on her skin evaporates quickly and cools her skin.
Explanation:
