Oooooo, that statement is not true. Countries create quotas and tariffs to <em>LIMIT</em> the volume of trade with other countries, including their neighbors.
Answer: (2) Use the Momentum Principle.
Explanation:
In fact, it is called the <u>Conservation of linear momentum principle,</u> which establishes the initial momentum 
of the asteroids before the collision must be equal to the final momentum 
after the collision, no matter if the collision was elastic or inelastic (in which the kinetic energy is not conserved).
In this sense, the linear momentum 
of a body is defined as:
Where 
is the mass and 
the velocity.
Therefore, the useful approach in this situation is<u> option (2)</u>.
To find the change in centripetal acceleration, you should first look for the centripetal acceleration at the top of the hill and at the bottom of the hill.
The formula for centripetal acceleration is:
Centripetal Acceleration = v squared divided by r
where:
v = velocity, m/s
r= radium, m
assuming the velocity does not change:
at the top of the hill:
centripetal acceleration = (4.5 m/s^2) divided by 0.25 m
= 81 m/s^2
at the bottom of the hill:
centripetal acceleration = (4.5 m/s^2) divided by 1.25 m
= 16.2 m/s^2
to find the change in centripetal acceleration, take the difference of the two.
change in centripetal acceleration = centripetal acceleration at the top of the hill - centripetal acceleration at the bottom of the hill
= 81 m/s^2 - 16.2 m/s^2
= 64.8 m/s^2 or 65 m/s^2
Physical science is defined as the study of observable phenomena in the universe.<span>The main idea of physical science is known as the "scientific method". </span>
<span>This method states: </span>
<span>1. observe a "real" ( not imaginary ) phenomena. </span>
<span>2. make a hypothesis ( or theory / idea ) that EXPLAINS this phenomena. </span>
<span>3. conduct a real experiment to test this hypothesis. </span>
<span>4. confirm that the experiment validates the original hypothesis and if necessary amend the theory. </span>
<span>This method is responsible for virtually every scientific explanation of every kind. </span><span>It has worked so well that the very communication you are having with me is a result of the wonders of physical science. </span>
<span>Hope your question was answered :)</span>
