Answer:
the signs of heat and work are; -Q and -W
Explanation:
The first law of thermodynamics is given by; ΔU = Q − W
where;
ΔU is the change in internal energy of a system,
Q is the net heat transfer (the sum of all heat transfer into and out of the system)
W is the net work done (the sum of all work done on or by the system).
Now, The system in this case is the tire and since the air gets warmer, heat must have left the system. Therefore Q is negative (-Q).
Since work is done by the system, W remains negative.
Thus, the signs of heat and work are; -Q and - W
It depends how large the object is. But, if it is 2 by 4, most likely the wood sieges more than the glass.
Hope this helps.
Answer:
Second option 6.3 N at 162° counterclockwise from
F1->
Explanation:
Observe the attached image. We must calculate the sum of all the forces in the direction x and in the direction y and equal the sum of the forces to 0.
For the address x we have:

For the address and we have:

The forces
and
are known

We have 2 unknowns (
and b) and we have 2 equations.
Now we clear
from the second equation and introduce it into the first equation.

Then

Then we find the value of 

Finally the answer is 6.3 N at 162° counterclockwise from
F1->
Yes it does (not to be mean its kinda stupid for you to ask)
Answer:
The answer is D. A Vacumn
Explanation:
Sound cannot travel through a vacuum. A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in.