Answer:
Part a)

Part b)
Direction = upwards
Explanation:
When ball is dropped from height h = 4.0 m
then the speed of the ball just before it will strike the ground is given as



Now ball will rebound to height h = 2.00 m
so the velocity of ball just after it will rebound is given as



Part a)
Average acceleration is given as



Part B)
As we know that ball rebounds upwards after collision while before collision it is moving downwards
So the direction of the acceleration is vertically upwards
Answer:
Because of the formula 
Explanation:
In this problem we are describing two different processes:
- Nuclear fission occurs when a heavy, unstable nucleus breaks apart into two or more lighter nuclei
- Nuclear fusion occurs when two (or more) light nuclei fuse together producing a heavier nucleus
In both cases, the total mass of the final products is smaller than the total mass of the initial nuclei.
According to Einsten's formula, this mass difference has been converted into energy, as follows:

where:
E is the energy released in the reaction
is the mass defect, the difference between the final total mass and the initial total mass
is the speed of light
From the formula, we see that the factor
is a very large number, therefore even if the mass defect
is very small, nuclear fusion and nuclear fission release huge amounts of energy.
Freeze wedging<span> is caused by the repeated freeze-thaw. </span>Frost wedging<span> occurs as the result of 9 % expansion of water when it is converted to ice. Cracks filled with water are forced further apart when it freezes. cycle.</span>