Answer:
Approximately 
.
Explanation:
The formula for the kinetic energy 
of an object is:
,
where
is the mass of that object, and
is the speed of that object.
Important: Joule (
) is the standard unit for energy. The formula for requires two inputs: mass and speed. The standard unit of mass is 
while the standard unit for speed is 
. If both inputs are in standard units, then the output (kinetic energy) will also be in the standard unit (that is: joules,
Convert the unit of the arrow's mass to standard unit:
.
Initial of this arrow:
.
That's the same as the energy output of this bow. Hence, the efficiency of energy transfer will be:
.
Answer:
The leaves of the electroscope move further apart.
Explanation:
This is what happens; when the positive object is brought near the top, negative charges migrating from the gold leaves to the top. This is because the negative charges in the gold are attracted by the positive charge. Thus, it leaves behind a net positive charge on the leaves, though the scope remains neutral overall. To that effect, the leaves repel each other and move apart. If a finger touches the top of the electroscope at the moment when the positive object remains near the top, it basically grounds the electroscope and thus the net positive charge in the leaves flows to the ground through the finger. However, the positive object continues to "hold" negative charges in place at the top. Ar this moment the gold leaves have lost their net positive charge, so they no longer repel, and they move closer together. If the positive object is moved away, the negative charges at the top are no longer attracted to the top, and they redistribute themselves throughout the electroscope, moving into the leaves and charging them negatively.
Thus, the leaves move apart from each other again and we now have a negatively charged electroscope. If a negatively charged object is now brought close to the top, but without touching, the negative charges already in the electroscope will be repelled down toward the leaves, thereby making them more negative, causing them to repel more, and hence move even further apart.
So, the leaves move further apart.
Answer:
The correct answer option is C
Explanation:
In a balanced chemical reaction mass of the reactant are always equal to mass of the products. Also known as Law of Conservation of Mass which states that " mass can nor be created nor be destroyed in a chemical reaction."
So, the mass of the reactant will be equal to the mass of products.That is 120 grams.
Hence, the correct answer option(C).
Answer:
A. moral development progressed through distinct, qualitatively different stages.
Explanation:
Kolhberg’s theory of moral development states that we progress through three levels of moral thinking that build on our cognitive development.
The correct option is the second one, which is: Every million years.
The impact of a 1-kilometer object on our planet, would cause significant consequences. As the astronomers have found in other terrestrial bodies, this kind of impact creates largers craters on the surface.
