Suppose you are doing an experiment where you determine the value of one parameter, say density of a liquid. You have two methods in doing this. By finding the mass and volume, and by using a densitometer. Reproducibility is when you get the same value of density for both methods. Replicability is when you have similar results in one method. So, replicability is a measure of precision, while reproducibility is a measure of accuracy.
The FIRST statement on the list is the definition of momentum, so that's the one that must be true.
The equation you use is Ke = 1/2mv^2. when you plug in the numbers that are given you get Ke= 1/2(4)(2^2) which gives you a Kinetic Energy of 8
Average velocity is displacement divided by time elapsed; Δv/Δt
You will need to use the information in the table you are given. Subtract: (final velocity - initial velocity) and divide by (final time - initial time).