Answer:
A) and B) are correct.
Explanation:
If the object is at rest, it means that no net force is exerted on it.
As the object experiences a downward gravitational force from Earth, in order to be at rest, it must experience an upward force with the same magnitude as the gravitational force on the object.
This force is supplied by the normal force, which can adopt any value in order to meet the condition imposed by Newton´s 2nd Law, and is always perpendicular to the surface on which the object is placed (in this case, the ground).
At a molecular level, this normal force is supplied by the bonded molecules of the ground that behave like small springs being compressed by the molecules of the object, exerting an upward restoring force upward on them.
So, the statements A) and B) are true.
Answer:
Car A has twice the energy of car B.
Explanation:
The kinetic energy of an object is given by :
Where
m is the mass
v is the speed of the object
Car A has twice the mass of Car B. Both travel at the same speed i.e.
So,
So, the kinetic energy of car A is twice of the kinetic energy of car B.
<h2>Answer: Sedimentary rocks
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Sedimentary rocks are formed from sediments and deposits of particles of various types, forms and sizes that are transported by air, wind or water, and then subjected to chemical processes to become rocks.
These types of rocks are usually found in the form of layers or strata in places where sediment accumulates due to the erosion of other materials, for example on the banks of rivers, in valleys, lakes (and any other type of body of water).
B. NaCl
All of the other answers contain a 2 or a number in general. Metals do not form covalent bonds. Alkali-halide salts are Ionic compounds. Ionic compounds form from bonding a metal and a non metal. Covalent bonds are formed by bonding non metals.
