The correct answers are:
1.
A plane landing on an aircraft carrier.
Rain sticking to a window.
Two train cars coupling together.
2. The total momentum is zero.
3. 3.6 (kg*m/s) (Option C)
Explanations:
1) In simple terms (not a textbook definition), perfectly inelastic collision is a collision in which two bodies stick together (or becomes one) after a collision. Now let us have a look at the options:
<em> A baseball bouncing off a bat</em>: After collision, the ball and the bat do not stick to one another; therefore, it is NOT a perfectly inelastic collision.
<em>Bumper cars bumping off of each other</em>: After collision, cars bump off of each other, making their collision elastic, not perfectly inelastic collision.
<em>A cue ball hitting an eight ball and stopping</em>: After collision, although the cue ball stops, but all of its momentum will be transferred to the eight ball; and eight ball will start moving, where is cue ball stops. Not a perfectly inelastic collision.
<em>A plane landing on an aircraft carrier</em>: After plan lands, the plane and the aircraft carrier will be incontent with each other; making their collision perfectly inelastic.
<em>Rain sticking to a window</em>: Rain drop sticking to a window means both stick together after a collision, making it a perfectly inelastic collision.
<em>Two train cars coupling together</em>: Again both cars are sticking together, making it a perfectly inelastic collision.
Hence the correct answers are:
A plane landing on an aircraft carrier.
Rain sticking to a window.
Two train cars coupling together
7) Always remember that in a closed system, the total momentum is conserved, meaning:
Total initial momentum = Total final momentum
<em>Initially, </em>bodies are <em>at rest</em>, the total initial momentum (mv) is zero (since (m+2m)*0 = 0; as v = 0). <em>As it is the closed system</em>, the total final momentum will be equal to the total initial momentum. As the total initial momentum is zero, the total final momentum will also be zero.
Hence the correct answer is: The total momentum is zero.
3) As you can see in the table, the initial momentum of each and every entry is equal to the final momentum. In the case of X, as the final momentum is 3.6 kg*m/s, the initial momentum will be same as the final momentum (by considering the pattern in the table); therefore X (the initial momentum) will be 3.6 kg*m/s.
Hence the correct answer is: X = 3.6 (Option C)
