We are given that the system “releases” heat of 2,500 J,
and that it “does work on the surroundings” by 7,655 J.
The highlighted words releases and does work on the surroundings
all refers to that it is the system itself which expends energy to do those
things. Therefore the action of releasing heat and doing work has both magnitudes
of negative value. Therefore:
heat released = - 2, 500 J
work done = - 7, 655 J
Which means that the total internal energy change of the
system is:
change in internal energy = heat released + work
<span>change in internal energy = - 2, 500 J + - 7, 655 J</span>
<span>change in internal energy = -10,155 J</span>
Mr. Hitch taught us about sedimentary, metamorphic, and igneous rocks. He described how they were formed, what they contain, and showed us samples of each. He is a good geologist.
The missing word and answer is: geologist.
Answer: The elevator must be accelerating.
Explanation:
As the tension force is opposing to the the force of gravity on the load which is hung vertically, and the tension force can adopt any value in order to comply with Newton's 2nd law, if the tension force is less than the force due to gravity, this means that all system is not in equilibrium, so it must be accelerating.
If we assume that the downward is the positive direction, we can write:
mg - T = ma
If T = 0.9 mg, ⇒ mg (1-0.9) =0.1 mg = m a ⇒a = 0.1 g , in downward direction.
Answer:
The German inventor of the movable-type printing press was Johannes Gutenberg.
Explanation:
- Johannes Gutenberg, the inventor of the mechanical movable type printing press introduced printing to Europe and started the Printing Revolution.
- In movable type technology of printing, the system used movable components to reproduce a document on the medium, usually paper. The advantages of this type of printing over woodblock printing were that the printing was quicker, the metal type pieces were more durable and the uniform lettering leads to typography and fonts.
- The metal movable-type printing press created by Johannes Gutenberg had the type pieces made from an alloy of lead, tin, and antimony. The casting of type pieces was done on matrix and hand molds. He created the first printed version of the Bible called the Gutenberg Bible using this printing technology.
- The movable-type printing press helped in the development of the Renaissance and the scientific revolution by the transmission of knowledge and laid the foundation of the modern knowledge-based economy.
