Answer:
U(0.0m) = 0J
U(5.5m) = 40.42 J
Explanation:
The gravitational potential energy is given by the following formula:

h: height
m: mass of the apple = 0.75kg
g: gravitational acceleration = 9.8m/s^2
When the apple is at 5.5m from the ground the gravitational potential energy is:

when the apple is on the ground you have:

“a point representing the mean position of the matter in a body or system.”
Answer: a disadvantage of using a ramp is that it is not safe
Answer:
An example in which liquid pressure phenomena can be used in daily life is in Water blasting
Explanation:
Water blasting refers application of pressurized water to remove materials from the surface of objects.
There are different varieties of water blasting, including;
Hydrocleaning; Cleaning enabled by the use of high pressure water
Hydrodemolition; Demolition or removal of concrete using pressurized water
Hydrojetting; The spraying of water under pressure on surfaces in order to remove surface contaminants.