Based on the principles of convection, conduction and thermal radiation, which scenario below is most similar to the following situation? you put a heating pad on your back after exercising. a) feeling a metal wire get warmer as you roast a marshmallow over a fire. b) warm air rising in a room where the air is moving. c) the sun warming up the roof on a house. d) cold water sinking in a pot of water being warmed up on the stove.

Option (A) is the correct answer.

Explanation:

In convection, conduction, and thermal radiation there is transfer of heat. When you put a heating pad on your back after exercising then there will be transfer of heat from heating pad to the human body.

Similarly, when we roast a marshmallow then metal wire on which marshmallow is placed gets warm due to thermal radiation from fire, there will be conduction as heat is transferring from marshmallow to the wire and also there will be convection process as marshmallow will melt and sink at the bottom.

Since metal wire is held by our hand so, we will also feel the heat.

Thus, we can conclude that the most similar of the following situation is feeling a metal wire get warmer as you roast a marshmallow over a fire.

the closer the planet is to the sun, the larger the gravity

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.