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.
The woman on the platform is correct because it is the pace of the man moving on the train not walking.
Answer:
The value is 
Explanation:
From the question we are told that
The temperature is 
Generally the root mean square speed of the oxygen molecules is mathematically represented as

Here R is the gas constant with a value 
M is the molar mass of oxygen molecule with value 
So

=> 
Answer:
2 m/s^2
Explanation:
a = v^2/r
a = (10m/s)^2 / 50m
a = 2 m/s^2
Leave a like and mark brainliest if this helped
Leave a like and mark brainliest if this helped