Explanation :
When a person is sliding with constant velocity, the forces that are acting on him are :
(1) Weight, W = mg where g is acceleration due to gravity.
(2) Friction forces acting opposite to the direction of motion.
(3) Normal force.
The forces acting on the person is balanced because the person is sliding with constant velocity.
From figure it is clear that, friction force is balanced by 
and normal is balanced by 
.
I believe it’s OH have a good day
Answer:
Option A
Explanation:
Mechanical waves requires some medium to travel through. They travel faster in the dense medium as compared to a free medium.
The speed of a mechanical wave is fastest in the solid medium and the slowest in the gaseous medium. Hence, as the wave traverses from gaseous medium to the solid medium, its speed increases.
Thus, option A is correct
Answer:
The electromagnetic force
Explanation:
There are four fundamental forces in nature:
- Gravitational force: it is the force that acts between any particles having mass. It is relevant only on very large scales (planets, stars), since it is the weakest of the 4 forces, so very large masses are needed in order to produce relevant effects.
- Electromagnetic force: it is the force that acts between particles with electric charge. It can be attractive or repulsive. It is the main force that acts between atoms and molecules.
- Strong nuclear force: it is the force that keeps the protons and the neutrons together inside the nucleus. It acts only on very short scales (only within the nucleus of the atom)
- Weak nuclear force: it is the force responsible for the radioactive decays of certain nuclei. It also acts on very short scales.
Therefore, the force that is responsible for binding atoms together to form molecules is the electromagnetic force.
