Answer:
Explanation:
For this problem, we just need to remember conservation of momentum, as there are no external forces in the horizontal direction:

where the suffix i means initial, and the suffix f means final.
The initial momentum will be:

as the second puck is initially at rest:

Using the unit vector
pointing in the original line of motion:



So:


Knowing the magnitude and directions relative to the x axis, we can find Cartesian representation of the vectors using the formula

So, our velocity vectors will be:


We got


So, we got the equations:

and
.
From the last one, we get:




and, for the first one:






so:

and


Answer:
The arrows always start at the magnet's north pole and point towards its south pole. When two like-poles point together, the arrows from the two magnets point in OPPOSITE directions and the field lines cannot join up. So the magnets will push apart (repel).
<h2>Answer: Gravitational attraction
</h2>
Gravity force causes the clouds of dust and gas to form a protostar. As this <u>attraction force</u> is responsible for gathering and compressing the existing elements in the cloud of gas and dust, heating them during this process.
Then, when the amount of material accumulated by gravitational contraction is large enough, and the temperature and pressure reached high enough, the <u>nuclear fusion</u> process will begin.
To understand it better: The hydrogen nuclei will begin to fuse, generating helium nuclei in the process and releasing huge amounts of energy.
It should be noted that the protostars radiate half of the energy contributed by the gravitational collapse and the other half is invested in heating its core.
Answer: 3.33 m/s
Explanation:
Assuming the questions is to convert 12 km/h to meter per second (m/s), let's begin:
In order to make the conversion, we have to know the following:

And:

Keeping this in mind, we can make the conversion:

Then:

Option (a) is correct.
Falling objects accelerate as they approach the ground.This is because of the force of gravity acting on the falling objects. so the velocity of these objects increases continuously as they approach the ground. the acceleration acting on the falling objects is a constant ( close to the surface of earth) and is called as acceleration due to gravity denoted by g. value of g=9.8 m/s².