Microwave ovens have a plate that rotates at a rate of about 7.0 rev/min. What is this in revolutions per second?
1 answer:
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Answer:
The value to be reported is 5.48V
Explanation:
The RMS (root mean square) is defined as the value of voltage that will produce the same heating effect, or power dissipation, in circuit, as this AC voltage.
The RMS voltage is also called effective voltage because it is just as effective as DC voltage in providing power to an element.
It is expressed as =
where Vm is the maximum or peak value of the voltage
In calculating the RMS of the voltage , we simply divide the peak voltage by square root of 2 (√2)
=
=
= 5.48 V
The resistance of the piece of wire is
where
is the resistivity of the copper
is the length of the piece of wire
is the cross sectional area of the wire
By substituting these values, we find the value of R:
Then, by using Ohm's law, we find the potential difference between the two points of the wire:
where
By substituting these values, we find the value of R:
Then, by using Ohm's law, we find the potential difference between the two points of the wire:
Answer:
The rifle barrel must be pointed at a height of 4.45cm above the target so that the bullet hits dead center.
Explanation:
First, we need to sketch the situation so we can have a better idea of what the problem looks like (Refer to uploaded picture).
So as you may see in the drawing, when pointing the rifle to the target, we can see it as a triangle, but in reality, the bullet will have a parabolic trajectory. Both points of view will help us determine what the height must be. In order to find it, we need to first determine at what angle the bullet should be shot. In order to do so we can use the range formula, which looks like this:
Where R is the range of the bullet (this is how far it goes before it has the
same height it was shot from), v is the original speed of the bullet, θ is the angle at which the bullet is shot and g is the acceleration of gravity.
We can solve this equation for theta, so we get:
so now we can substitute the given data:
so we get:
θ=0.05614°
once we get the angle, we can look at the triangle diagram. From the drawing we can see that we can use the tan function to find the height:
so we can solve this for h, so we get:
which yields:
or
