A. A car comes equipped with side airbags. I don't know how I'm supposed to show work but that's the answer
I think the correct answer would be that the temperature of the clouds that made the very first stars where thought to be higher since the clouds are made up of hydrogen and helium. Hope this answers the question. Have a nice day.
The runner has initial velocity vector

and acceleration vector

so that her velocity at time
is

She runs directly east when the vertical component of
is 0:

It's not clear what you're supposed to find at this particular time... possibly her position vector? In that case, assuming she starts at the origin, her position at time
would be

so that after 10.4 s, her position would be

which is 19.9 m away from her starting position.
The subscript for nitrogen in hydrazine, N2H4 is 2.
In chemistry, when writing the chemical formula of chemical compounds, subscripts refers to the numerical numbers that are sometimes put at the base of some chemical symbols. The subscripts are used to indicate the number of atoms that are present in each element. For example, in hydrazine, the subscript 2 indicates that two atoms of nitrogen are present, while the subscript 4 indicates that four atoms of hydrogen are presents.