Answer:

Explanation:
<u>The total momentum of a system is defined by:</u>

Where,
is the total momentum or it could be expressed also as
.
and
represents the masses of the objects interacting in the system.
and
are the velocities of the objects of the system.
<em>Remember: </em><em>The momentum is a fundamental physical magnitude of vector type.</em>
We have:


We are going to take the east side as positive, and the west side as negative. Then the velocity of the car B, has to be <u>negative</u>. It goes in a different direction from car A.

Then the total momentum of the system is:

If the objects comprise a gas, then the first object contains more
thermal energy (heat) than the second object.
If the objects are solid, then you can't draw any conclusion unless
both objects have the same total mass. If that's the case, then the
first object must be moving faster than the second one.
Let us assume the upstream rowing rate of Alicia = x
Let us assume the downstream rowing rate of Alicia = y
We already know that
Travelling time = Distance traveled/rowing rate
Then
6/(x + 3) = 4/x
6x = 4x + 12
6x - 4x = 12
2x = 12
x = 6
Then
Rowing rate of Alicia going upstream = 6 miles per hour
Rowing rate of Alicia going downstream = 9 miles per hour.
<span>1.0 m/s
Momentum = mass x velocity
Total Momentum before any collision = total momentum afterwards
4.0 x 3.0= 12 :g x momentum before (x g because using weight)
Afterwards, if the velocity of the two joined is v then we get:
'momentum x g'=12v
so 12v=12
so v=1m/s</span>
The best answer to the question that is being stated above would be the first choice. To disprove the claims of the student that you need more protons to have more reactivity, then you proceed to compare the reactivities of lithium (Li) and krypton (Kr). Krypton has more protons than Lithium, but it is less reactive because it is a noble gas.