Explanation:
The five basic postulate of kinetic molecular theory includes:
1) All gases consist of large amount and numbers of tiny particles that are far apart from each other and also relative to their size.
2) The collisions between gas particles and gas particles against container walls is refer to as elastic collision.
3) All gas particles are in a continuous random and rapid motion. They possess kinetic energy which is energy of motion.
4) There are no attractive force between gas particles.
5) The temperature of a gas depends on the average kinetic energy of the gas particle.
Steam is often used as a central heating system when heating many buildings froma central location. So the correct option for the given question is option "D". Steam is actually generated ina single room or place mechanically or by useing fossil fuel or solar energy and then it is passed through pipelines to several rooms and buidings. This kind of system is mostly used when heating several rooms or building at once. Electric heaters are normally avoided as the cost of electricity is far higher than any other source of heating.
Complete Question
A 95 kg clock initially at rest on a horizontal floor requires a 650 N horizontal force to set it in motion. After the clock is in motion, a horizontal force of 560 N keeps it moving with a constant velocity. Find the coefficient of static friction and the coefficient of kinetic friction.
Answer:
The value for static friction is 
The value for static friction is 
Explanation:
From the question we are told that
The mass of the clock is 
The first horizontal force is 
The second horizontal force is 
Generally the static frictional force is equal to the first horizontal force
So

=> 
=> 
Generally the kinetic frictional force is equal to the second horizontal force
So



Answer:
C. At the instant the ball reaches its highest point.
Explanation:
When a body is thrown up, it tends to come down due to the influence of gravitational force acting on the body. The body will be momentarily at rest at its maximum point before falling. At this maximum point, the velocity of the body is zero and since force acting on a body is product of the mass and its acceleration, the force acting on the body at that point will be "zero"
Remember, F = ma = m(v/t)
Since v = 0 at maximum height
F = m(0/t)
F = 0N
This shows that the force acting on the body is zero at the maximum height.
Answer:

& 
Explanation:
Given:
- interior temperature of box,

- height of the walls of box,

- thickness of each layer of bi-layered plywood,

- thermal conductivity of plywood,

- thickness of sandwiched Styrofoam,

- thermal conductivity of Styrofoam,

- exterior temperature,

<u>From the Fourier's law of conduction:</u>

....................................(1)
<u>Now calculating the equivalent thermal resistance for conductivity using electrical analogy:</u>




.....................(2)
Putting the value from (2) into (1):


is the heat per unit area of the wall.
The heat flux remains constant because the area is constant.
<u>For plywood-Styrofoam interface from inside:</u>



&<u>For Styrofoam-plywood interface from inside:</u>


