Answer:
To create an electric potential difference between the ends of the conductor.
Explanation:
For current to flow, there must exist an electric potential difference between the ends of the conductor. This PD is provided by the electromotive force stored within the battery. Unless there is a connection between the terminals no PD will exist between the terminals.
Answer:
none of the above
Explanation:
The actual answer is '91 protons'. In fact, the beta decay of the thorium-234 is the following:

where inside the nucleus of Thorium (90 protons), a neutron turns into an electron (the beta particle) + a proton. Therefore, the resulting nucleus (which is Protoactinium) has a total of 90+1 = 91 protons.
So, the correct answer would be '91 protons'.
100/5= 20, 20 seconds is the time needed.
Answer:
1. The automobile is traveling due east and is speeding up.
2. The car is traveling due east and is is slowing down.
3. The automobile is traveling due east at a constant speed.
4. The car is traveling due west and is slowing down.
5. The automobile is traveling due west and is speeding up.
6. The automobile is traveling due west at a constant speed.
7. The automobile is accelerating due east from rest.
8. The automobile is accelerating due west from rest.
Explanation:
The key to understanding this is:
When the acceleration and initial velocity of the automobile have the same sign (positive or negative) then the automobile is speeding up. Explained further, if acceleration and the initial velocity are both positive or they are both negative the automobile is speeding up but whenever they have opposite signs (that is acceleration is positive and initial velocity is negative or vice versa) the automobile is slowing down. When the acceleration is zero the automobile is maintaining a unform motion at a constant speed (the speed is not changing with time). The + or - sign indicates the direction of travel. In this case east is + and west is -. It is my pleasure answering this question. I hope you find it helpful. Thank you.
You said that the useful output power from the model is 6 watts. You also said that the model is 80% efficient. We have no reason to doubt your word, so we know that
(useful output) / (input power) = 80% or 0.8
(6 watts) / (input power) = 0.8
Multiply each side by (input power): 6 watts = (0.8) (input power)
Divide each side by 0.8 : Input power = (6 watts/ 0.8)
<em>Input power = 7.5 watts</em>