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.
From the formula of W = F·d , becuase we have the values for W and d we can find F
W = F·d
F= W/d
= 250/5
= 50 N
40 N of force was applied
Answer:
As of right now the techology has not been invented to time travel
if we were to time travel to the future from where that person travled from would be the past and to them the people from where they came from are living in the past
Explanation:
Power is defined as the rate at which the body is doing work:

Work is defined as displacement done by the force times that displacement:

We know that we need 62N to move the box, so when we apply this force along the path of 10m we have done:

of work.
Now we just divide that by 5s to get how much power is required: