Answer:
Gamma rays occupy the short-wavelength end of the spectrum; they can have wavelengths smaller than the nucleus of an atom. Visible light wavesare one-thousandths the width of human hair--about a million times longer than gamma rays. Radio waves, at the long-wavelength end of the spectrum, can be many meters long.
Answer:
D. Hydrogen combines with oxygen to form water.
Explanation:
Hydrogen combining with oxygen to form water is a typical example of chemical reaction.
During a chemical reaction, atoms of elements are rearranged. Most chemical reactions obey the law of conservation of mass which states that "matter is neither created nor destroyed in a chemical reaction but atoms are simply rearranged".
The other choices given are nuclear reactions. In such reactions, atoms are not rearranged but are simply destroyed and made in the process.
Answer:
B
Explanation:
Technically none of them are completely correct, however the Professor likely just wants you to recognize that endothermic means absorbing heat which therefore means that the product should be hotter than than the reactants.
Answer:
They collide, couple together, and roll away in the direction that <u>the 2m/s car was rolling in.</u>
Explanation:
We should start off with stating that the conservation of momentum is used here.
Momentum = mass * speed
Since, mass of both freight cars is the same, the speed determines which has more momentum.
Thus, the momentum of the 2 m/s freight car is twice that of the 1 m/s freight car.
The final speed is calculated as below:
mass * (velocity of first freight car) + mass * (velocity of second freight car) = (mass of both freight cars) * final velocity
(m * V1) + (m * V2) = (2m * V)
Let's substitute the velocities 1m/s for the first car, and - 2m/s for the second. (since the second is opposite in direction)
We get:
solving this we get:
V = - 0.5 m/s
Thus we can see that both cars will roll away in the direction that the 2 m/s car was going in. (because of the negative sign in the answer)
