Answer:
A. Its unique strength allows predetermined engineering stresses to be placed in members to counteract stresses that occur when the unit is subjected to service loads
Explanation:
Prestressed concrete is a structural material that allows for predetermined, engineering stresses to be placed in members to counteract the stresses that occur when they are subject to loading.
It combines the high strength compressive properties of concrete with the high tensile strength of steel.
‘Building Construction Handbook’ (6th ed.), CHUDLEY, R., GREENO, R., Butterworth-Heinemann (2007)
Then the correct answer is:
A. Its unique strength allows predetermined engineering stresses to be placed in members to counteract stresses that occur when the unit is subjected to service loads
Answer:
The magnitude of the force of friction equals the magnitude of my push
Explanation:
Since the crate moves at a constant speed, there is no net acceleration and thus, my push is balanced by the frictional force on the crate. So, the magnitude of the force of friction equals the magnitude of my push.
Let F = push and f = frictional force and f' = net force
F - f = f' since the crate moves at constant speed, acceleration is zero and thus f' = ma = m (0) = 0
So, F - f = 0
Thus, F = f
So, the magnitude of the force of friction equals the magnitude of my push.
Answer:
Compound.
Explanation:
A compound is a substance formed when two or more elements are chemically joined. Water, salt, and sugar are examples of compounds. When the elements are joined, the atoms lose their individual properties and have different properties from the elements they are composed of.
Answer:
a)
, b) 
Explanation:
a) The minimum coeffcient of friction is computed by the following expression derived from the Principle of Energy Conservation:




b) The speed of the block is determined by using the Principle of Energy Conservation:




The radius of the circular loop is:


