Answer:
B
Explanation:
Protons have a positive electrical charge of +1,
Electrons have a negative charge of -1,
Neutrons have a neutral charge of about 0.
Answer:
As the skydiver falls to the Earth, she experiences positive acceleration only due to gravity.
Explanation:
As the skydiver falls to the Earth, she experiences friction in the form of air resistance which tries to slow her down and is proportional to the her velocity. So it cannot have a positive acceleration as it acts in opposite direction to slow her down.
Inertia during skydiving is experienced when we open an parachute, the parachute slows down the speed of are descent hence changing our inertia of motion with a velocity.
Only the Earth's, gravitational field has an positive acceleration as it pulls us towards the Earth, hence increasing our velocity.
Answer:
A. Adjusts how far down the piston travels
Explanation:
This type of engine changes the possition of the piston in order to modify the compression chamber volume and therefore the compression ratio of the engine. The volume of the chamber is proportional to the run of the piston (how far down the piston travels)
This engine is used to achive the optimal compression rate in each individual stage.
Answer:
c. Fission and fusion are two processes that release very little amounts of energy.
Explanation:
This statement is false. In fact, both fission and fusion are processes which release very large amounts of energy. The statement can be rewritten as it is true as follows:
"Fission and fusion are two processes that release very large amounts of energy."
Fission occurs when a large nucleus break apart, splitting into smaller nuclei, while fusion occurs when two light nuclei combine together into a larger nucleus. In both cases, the mass of the reactants is larger than the mass of the final products, so some of the mass has been converted into energy, according to Einstein's equation:
where
E is the energy released
is the mass lost in the process
c is the speed of light
Since c is a very large number (
), we see that even a very small mass causes the released of a huge amount of energy, so both fission and fusion release large amounts of energy.
