Texts:
1.
a. A block of mass m = 22 kg is thrown downward from a height of h = 1.6 m/s with an initial speed of v = 2.4 m/s. If the block hits the ground with a speed of v# = 5.0 m/s, then find the change in thermal energy of the system where the system = earth + block + air. In other words, compute ΔEthermal.
b. Did the thermal energy increase or decrease? Explain how you know.
18.
a. Micro
between mechanical energy and internal energy using the ideas of
In our notes, which of the internal energies did we incorporate with force? HELP: We only did numerical examples of just one type. Name it. .. u[Cx,|6,2/ {,U/, '2, -,, :p/,u /,u [,, ,/(5 p;2|C] L u| In an isolated system, explain when (1) total energy = mechanical energy versus when (2) total energy = mechanical + internal. HELP: In your explanation use the word non-conservative force and work. In a general isolated system where both conservative and non-conservative forces coexist, there is a transfer of mechanical energy to internal energy: true or false. Write the "transfer equation".
;epu zb 1b-b=1byuogenbup -b pue *:^e/ vu , , pu up sc -b , ,un /, n s ib / "_,,,,_
19.
Seen is a ray change diagram shown in notes: Fact when the block-spring interaction goes through friction then the mechanical
Surroundings - Nothing
w.-o
When the block stays on the surface, does that mean the work is positive or negative?
b. Complete the sentence ORORYIS - always the sum of Work = 0. What does the word "surface in the system" (spring + block + surface) mean? Explain. True or False: The system is isolated. Explain how you know this from the diagram. HELP: Don't confuse the concept of system versus surroundings with the word environment. What does the symbol W-,) mean in the diagram? What is the work, W?
What does the symbol ΔE stand for; give it a short sentence description.
h. 5;|ns. /ye(uree; )+ 5>-en ,/,;e s/z/e s ,, [eguy muo a/ in what sign for E?
i. Explain how you know from the sign of E.
10
In the diagram, the system's total energy is the sum of both mechanical and thermal. Since E. E hat cces this mean? Give a sentence as your answer. Continuing part (), defining the system energy to be the sum of mechanical and thermal, what does this mean about changes in the total system energy? Continuing part (k), what coe