The options attached to the question are given below:
A. The substances that are formed.
B. The substances that are changed.
C. The starting materials.
D. The chemical ingredients
ANSWER
The correct option is C.
A chemical reaction is made up of two distinct parts, which are reactants and products. The reactants refers to the starting material of the chemical process, which react together under suitable conditions. The products on the other hand refers to the new substance that is formed as a result of the reaction of the reactants. The reactants are usually find at the left side of chemical equations while the product is found at the right.
Given:
Height of tank = 8 ft
and we need to pump fuel weighing 52 lb/
to a height of 13 ft above the tank top
Solution:
Total height = 8+13 =21 ft
pumping dist = 21 - y
Area of cross-section =
=
=16

Now,
Work done required = 
= 
= 832
)
= 113152
= 355477 ft-lb
Therefore work required to pump the fuel is 355477 ft-lb
Gravitational Potential Energy, GPE = mgh
Where m is your mass in kg, g is acceleration due to gravity = 9.8 m/s², and h is the height in m.
The only value that be controlled here is the height h. The mass is constant, and acceleration due to gravity at that place is constant.
But h can be varied.
Hence to increase the gravitational potential energy between yourself and Earth is to increase the height h.
This can be done by climbing up a table, or climbing up a building through the stairs, or by using a lift.
Answer:
gravity and normal force I think