Answer:

Explanation:
Momentum is a vector quantity that represents the "amount of motion" of an object.
Mathematically, the momentum of an object is given by

where
m is the mass of the object
v is the velocity
Since momentum is a vector, it also has a direction, which is the same as the velocity.
Therefore, if we have two objects, the total momentum of the two objects will be obtained from the vector sum of the individual momenta of the two objects.
In this problem we have:
is the momentum of object A
is the momentum of object B
Therefore, the total momentum of objects A and B can be obtained by adding each components of A to the corresponding component of B, so:

So the total initial momentum is

Answer:
The electromagnetic force
Explanation:
There are four fundamental forces in nature:
- Gravitational force: it is the force that acts between any particles having mass. It is relevant only on very large scales (planets, stars), since it is the weakest of the 4 forces, so very large masses are needed in order to produce relevant effects.
- Electromagnetic force: it is the force that acts between particles with electric charge. It can be attractive or repulsive. It is the main force that acts between atoms and molecules.
- Strong nuclear force: it is the force that keeps the protons and the neutrons together inside the nucleus. It acts only on very short scales (only within the nucleus of the atom)
- Weak nuclear force: it is the force responsible for the radioactive decays of certain nuclei. It also acts on very short scales.
Therefore, the force that is responsible for binding atoms together to form molecules is the electromagnetic force.
Answer:
7.50 m/s^2
Explanation:
The period of a pendulum is given by:
(1)
where
L = 0.600 m is the length of the pendulum
g = ? is the acceleration due to gravity
In this problem, we can find the period T. In fact, the frequency is equal to the number of oscillations per second, so:

And the period is the reciprocal of the frequency:

And by using this into eq.(1), we can find the value of g:

Yes because it helps them locate their position and direction
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.