The chemical symbol always begins with a capital letter.
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Is there suppose to be an image?
Answer:

Explanation:
First we have to find the time required for train to travel 60 meters and impact the car, this is an uniform linear motion:

The reaction time of the driver before starting to accelerate was 0.50 seconds. So, remaining time for driver is 1.5 seconds.
Now, we have to calculate the distance traveled for the driver in this 0.5 seconds before he start to accelerate. Again, is an uniform linear motion:

The driver cover 10 meters in this 0.5 seconds. So, the remaining distance to be cover in 1.5 seconds by the driver are 35 meters. We calculate the minimum acceleration required by the car in order to cross the tracks before the train arrive, Since this is an uniformly accelerated motion, we use the following equation:

Not possible. The air is actually able to travel sound throughout itself without any difficulties. I believe, air actually brings sound closer to the people farther away ; It really helps to stretch sound.
Answer:
Explanation:
Given
Two masses
and
is released and there is tension T in the string
Suppose a is the acceleration of the system
Therefore from Diagram
For 

------1
for m_2 body

-------2
From above two Equation it is said that Tension is greater than m_1g and less than m_2g
