Initially, the experiment has only potential energy (since total energy is the sum of kinetic and potential energy). And at the end, the experment has only kinetic energy.
Potential energy is high and kinetic is equal i believe.
Answer:
a) 
b) 
c) 
d) Displacement = 22 m
e) Average speed = 11 m/s
Explanation:
a)
Notice that the acceleration is the derivative of the velocity function, which in this case, being a straight line is constant everywhere, and which can be calculated as:

Therefore, acceleration is 
b) the functional expression for this line of slope 4 that passes through a y-intercept at (0, 3) is given by:

c) Since we know the general formula for the velocity, now we can estimate it at any value for 't", for example for the requested t = 1 second:

d) The displacement between times t = 1 sec, and t = 3 seconds is given by the area under the velocity curve between these two time values. Since we have a simple trapezoid, we can calculate it directly using geometry and evaluating V(3) (we already know V(1)):
Displacement = 
e) Recall that the average of a function between two values is the integral (area under the curve) divided by the length of the interval:
Average velocity = 
Answer:
Kinetic energy of bigger rock will be more than that of smaller one.
Explanation:
Kinetic energy of the rock is given by,
Kinetic energy = 
As velocity of both the rocks are same. Thus, kinetic energy is directly proportional to the mass of the rock
Kinetic energy ∝ mass
So, For greater mass kinetic energy will be greater and for smaller mass kinetic energy will be smaller.
Hence, Kinetic energy of bigger rock will be more than that of smaller one.
Answer:
The Earth's magnetism is generated in the core, which is composed of iron that is constantly churning
Explanation:
Magnetic fields are produced by charges in motion, therefore by currents.
The outer core of the Earth consists mainly of melted iron that is in constant motion. This iron in motion actually acts as a giant current, and therefore it is responsible for the creation of the Earth's magnetic field.
The magnetic field of the Earth is very weak, in fact its magnitude is on average between 25 and 65 microtesla (for comparison, normal magnets can even produce magnetic fields of a few millitesla).
However, its role is very important for the Earth: in fact, it provides a shield that blocks most of the harmful radiation coming from the Sun.