Explanation:
Speed is distance over time.
500 km / 2 hr = 250 km/hr
Velocity is speed and direction.
250 km/hr north
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.
The total work done by the electric field on the charge is given by the scalar product between the electric force acting on the charge and the displacement of the charge:

where the force is F=qE, d=0.556 and

. Using the value of q and E given by the problem, we find
Answer:
a. stay the same for very long
Explanation:
It is rare for any motion to stay the same for a very long time. The force applied on a body causes changes in the magnitude of motion.
- For motion to remain constant, there must not be a net force acting on the body
- All the forces on the body must be balanced.
- This is very hard to come by.
- Motion changes very frequently.