Answer:
An external force is a force that acts on an object within the system from outside the system. This type of force is different than an internal force, which acts between two objects that are both within the system. The net external force combines these two definitions; it is the total combined external force
Explanation:
ig the answer is true
Well it is definitely answer B because when light is on for a long time it heats up a lot.the thermometer obviously went up which means the light bulb had more energy and was hotter than the start of it
Answer:
Explanation:
Let the angle between the first polariser and the second polariser axis is θ.
By using of law of Malus
(a)
Let the intensity of light coming out from the first polariser is I'
.... (1)
Now the angle between the transmission axis of the second and the third polariser is 90 - θ. Let the intensity of light coming out from the third polariser is I''.
By the law of Malus

So,



(b)
Now differentiate with respect to θ.


<u>Answer:</u> The voltage needed is 35.7 V
<u>Explanation:</u>
Assuming that the resistors are arranged in parallel combination.
For the resistors arranged in parallel combination:

We are given:

Using above equation, we get:

Calculating the voltage by using Ohm's law:
.....(1)
where,
V = voltage applied
I = Current = 3.75 A
R = Resistance = 
Putting values in equation 1, we get:

Hence, the voltage needed is 35.7 V