A.rock breaking and D movement below ground
Both valves are closed during the power stroke.
While the fuel is burning in the cylinder, you want
all the force of the expanding gases to push the
piston down ... you don't want any of the gases
or their pressure escaping.
If either of the valves was open, even just a crack,
then part of the gases would go blooey out the valve,
and some pressure would be lost that's supposed to be
pushing the piston.
Answer:
1 P = 0.5
2 P = 0.3
3 P = 0.01
Explanation:
The probability formula is

Where P is the probability V is the volume while N is the number of distinguishing particles
So for N = 1 and 

= 0.5
For N = 1 and 

= 0.3
For N = 1 and 

= 0.01
Answer:
1500 per second.
Explanation:
vibrations = 1.5 kilohertz
1.5×1000=1500
the answer is 1500 per second.