Melting
we know that ice melts at 0 ⁰C. in the graph, at position B, the temperature is constant, which indicates that phase change is taking place there. at B , from the graph , we also notice that the temperature is constant at value 0 ⁰C. this indicates that ice at 0 ⁰C is converting to water at 0 ⁰C there at position B in the graph.
hence the correct choice is Melting.
An example of a high specific heat is water’s specific heat, which requires 4.184 joules of heat to increase the temperature of 1 gram of water 1 degree Celsius. Scientifically, water’s specific heat is written as: 1 calorie/gm °C = 4.186 J/gm °C.
Positive feedback interactions in earth’s systems are always a result of human action is a FALSE statement.
<u>Explanation:</u>
Earth is a unstable equilibrium which tends to move out of equilibrium, but several other factors try to bring it back in equilibrium again. Earth has a different actions going on both on its surface and also inside it.
Human can alter, or can modify a very small part of the events that occur on earth’s surface. But they don’t have any control on what’s going inside earth’s core. So positive feedback interactions are not only the results of human interaction, but also different other factors.
1. All the relevant resistors are in series, so the total (or equivalent) resistance is the sum of the resistances of the resistors: 20 Ω + 80 Ω + 50 Ω = 150 Ω [choice A].
2. The ammeter will read the current flowing through this circuit. We can find the ammeter reading using Ohm's law in terms of the electromotive force provided by the battery: I = ℰ/R = (30 V)(150 Ω) = 0.20 A [choice C].
3. The voltmeter will measure the potential drop across the 50 Ω resistor, i.e., the voltage at that resistor. We know from question 2 that the current flowing through the resistor is 0.20 A. So, from Ohm's law, V = IR = (0.20 A)(50 Ω) = 10. V, which will be the voltmeter reading [choice F].
4. Trick question? If the circuit becomes open, then no current will flow. Moreover, even if the voltmeter were kept as element of the circuit, voltmeters generally have a very high resistance (an ideal voltmeter has infinite resistance), so the current moving through the circuit will be negligible if not nil. In any case, the ammeter reading would be 0 A [choice B].
Complete Question
A person throws a pumpkin at a horizontal speed of 4.0 m/s off a cliff. The pumpkin travels 9.5m horizontally before it hits the ground. We can ignore air resistance.What is the pumpkin's vertical displacement during the throw? What is the pumpkin's vertical velocity when it hits the ground?
Answer:
The pumpkin's vertical displacement is 
The pumpkin's vertical velocity when it hits the ground is 
Explanation:
From the question we are told that
The horizontal speed is 
The horizontal distance traveled is 
The horizontal distance traveled is mathematically represented as
Where t is the time taken
substituting values
=> 
Now the vertical displacement is mathematically represented as
now the vertical velocity before the throw is zero
So
Now the final vertical velocity is mathematically represented as
substituting values
