Work is done when a force acts on an object AND the object moves in the direction of the force.
-- <em>Pulling a trailer up a hill. YES. </em> The trailer is moving in the direction of the pulling force.
-- Carrying a box down a corridor. No. The box is not moving in the direction of gravity (down) OR in the direction of your arm (down the corridor).
-- Suspending a heavy weight with a strong chain, No. There's a force (gravity) acting on the weight, but the weight is not moving at all.
-- Pushing against a locked door. No. There's a force (your muscles) acting on the door, but he door is not moving at all.
Gravitational potential energy is defined as the amount of energy an object possesses at a given height above the Earth's surface. The equation for gravitational energy is E = mgh. Here, m is the mass of the object, g is the acceleration due to gravity, and h is the height above the Earth's surface. Hence, the answer is E = 2000kg x 9.81m/s^2 x 2m = 39240 Joules.
Answer:
Here, he is able both to share his own suffering and—in a way that Mammy cannot—insist on his love for Laila. Babi's dream for leaving Afghanistan is, ironically, based in his love for the country—a love he thinks can be better kept alive by continuing to celebrate its culture and cuisine abroad.JThe nucleus of some isotopes will spontaneously undergo nuclear decay. These isotopes are said to be radioactive. What causes the nucleus of an isotope to be radioactive?
The electric force and nuclear forces are in opposition to each other
Nuclear forces disintegrate protons
There are too many electrons in its orbitals
The electric force causes electrons to be released
(please help i genuinely cant find out why)Babi had wanted Laila and Tariq to understand their country's living, breathing heritage—a heritage quite apart from the violence and turmoil of the national wars. The Buddhas, testimony to an ancient community of monks that lived in caves within the cliffs, symbolize the cultural richness of this national heritageAs an unstable atom tries to reach a stable form, energy and matter are released from the nucleus. This spontaneous change in the nucleus is called radioactive decay. When there is a change in the nucleus and one element changes into another, it is called transmutation.Carbon-14 is unstable and undergoes radioactive decay with a half-life of about 5,730 years (meaning that half of the material will be gone after 5,730 years). This decay means the amount of carbon-14 in an object serves as a clock, showing the object's age in a process called “carbon dating.”Nuclear decay occurs when the nucleus of an atom is unstable and spontaneously emits energy in the form of radiation. The result is that the nucleus changes into the nucleus of one or more other elements. These daughter nuclei have a lower mass and are more stable (lower in energy) than the parent nucleus.
THere is a standard relationship that gives this result where the capacity of the capacitor is used:
.
We know though that Q/c=V and thus we can use the relationship:
E=Q*V/2 where we have just substituted in. If we also take into account that Q=VC, we can also get that E=V^2*C/2.
We are given the charge and the potential, so the best expression to use is the middle one.
Substituting, we get that E=1/2*8*10^(-10)*20=8*10^(-9).
The answer is B
