Answer:
The answer is D the rising of warm air pushing down cool air.
Answer:
Explanation:
Given
car A had a head start of 
and it starts at x=0 and t=0
Car B has to travel a distance of 
where
is the distance travel by car A in time t
distance travel by car A is

For car B with speed 



Answer:
A. It is always a positive force
Explanation:
Hooke's law describes the relation between an applied force and extension ability of an elastic material. The law states that provided the elastic limit, e, of a material is not exceeded, the force, F, applied is proportional to the extension, x, provided temperature is constant.
i.e F = - kx
where k is the constant of proportionality, and the minus sign implies that the force is a restoring force.
The applied force can either be compressing or stretching force.
<span>Scientific theories are tested and proven over time; they are then considered scientific laws.
Sometimes however, they are proven wrong, and so they do not become laws
hope this helps</span>
From the first law of thermodynamics, we use the equation expressed as:
ΔH = Q + W
where Q is the heat absorbed of the system and W is the work done.
We calculate as follows:
ΔH = Q + W
ΔH = 829 J + 690 J = 1519 J
Hope this answers the question. Have a nice day.