Answer:
(a) See explanation below.
(b) ω = 5.24rad/s.
Explanation:
(a) The tangential speed at the outer edges of the sprocket and wheel are the same because the wheel does not slip and as a result the rotational kinetic energy delivered to/by the pedal transmitted uniformly throughout the chain and sprocket system. This energy causes the outer edges to move equal linear distances in equal time intervals.
Let s be the distance covered in time t
Let the tangential speed of the pedal sprocket be v1 and that of the wheel sprocket be v2
S = v1t = v2t since the time interval is the same and the wheel does not slip.
v1 = v2 = v
(b)The radius of the pedal sprocket r = 11cm = 0.11m
The pedal rotates 1 rev in every 1.2s. One revolution is equal to 2π radians.
So the angular speed is equal to ω = 2π/1.2s = 5.24rad/s
ω = 5.24rad/s
Answer:
Explanation:
The function of resistance in an electronic circuit is that it helps to limit the current in the circuit, so as to prevent it from high currents.
The resistor helps to limit the charge flowing through the circuit and also limits the flow rate of the charge.
The resistor opposes the flow of current through the circuit.
The initial and final voltage across the capacitor decreases.
Answer:
D. Cold, dry air
(Just took the quiz and got it right, hope this helps :3)
Answer: <u>D. An AC circuit</u>
Explanation:
I took it on a test and it was correct ; )
Before a person walks through burning coal, the person will make sure their feet are very wet. When they start walking on the coal, this moisture will evaporate and form a protective gas layer underneath the person's feet. You can see examples of this if you happen to drip some water on a hot stove or any very hot surface. The water will very easily glide around on top of a newly formed layer of air underneath it -- like air hockey pucks on an air hockey table. Note that when someone walks through burning coal, typically this is also done very quickly to prevent a great deal of exposure to possible harm. By walking quickly, thinking positively, and letting the water cushion you from immediate danger over a short distance, such a task is possible. You may have also heard of physics teachers demonstrating how this principle works by sticking their hand first in a bucket of water and then quickly in a bucket of boiling molten lead. In the lead, their hand is protected briefly by a layer of gas from the evaporated water (the water vapor). I'm fairly sure that there is a name for this particular layer of gas, but I'm afraid the name is beyond me at the moment. In other words, water vapor has a low heat capacity and poor thermal conduction. Very often, the coals or wood embers that are used in fire walking also have a low heat capacity. Sweat produced on the bottom of people's feet also helps form a protective water vapor. All of this together makes it possible, if moving quickly enough, to walk across hot coals without getting burned. WARNING: Do not attempt to perform any of the actions described above. You can seriously injure yourself. Answered by: Ted Pavlic, Electrical Engineering Undergrad Student, Ohio St. (citing my source)
