You need to observe the car at two different times.
-- The first time:
You write down the car's speed, and the direction it's pointing.
-- The second time:
You write down the car's speed and the direction it's pointing, again.
You take the data back to your lab to analyze it.
-- You compare the first and second speed. If they're different,
then the car had acceleration during the time between the two
observations.
-- You compare the first and second direction. If those are different,
even if the speeds are the same, then the car had acceleration during
the time between the two observations.
(Remember, "acceleration" doesn't mean "speeding up".
It means any change in speed or direction of motion.)
Since momentum is a vector quantity, take any direction as positive and other as negative. Answer won't change.
Answer:

Explanation:
Given that:
p = magnitude of charge on a proton = 
k = Boltzmann constant = 
r = distance between the two carbon nuclei = 1.00 nm = 
Since a carbon nucleus contains 6 protons.
So, charge on a carbon nucleus is 
We know that the electric potential energy between two charges q and Q separated by a distance r is given by:

So, the potential energy between the two nuclei of carbon is as below:

Hence, the energy stored between two nuclei of carbon is
.
Answer: (B) There is complete destructive interference between the incoming and reflected waves
Explanation:
For example, if you pluck a guitar the waves will travel back and forth. They consist of nodes and anti-nodes. It is created, when the wave traveling to one side and bounces of the other end and comes back. As it travels to the other side, it is reflected thus, comes back. So standing waves occurs when there is interference.
When the wave is produced, the points where the string is not moving are called nodes and where they are moving are called anti-nodes. The positions where nodes are produced, destructive interference occurs and where anti-nodes are produced, constructive interference occurs