I believe it’s a liquid inside a beaker on a hot Bunsen burner (c)
This is because : Everyday Examples of Convection
Boiling water - The heat passes from the burner into the pot, heating the water at the bottom. Then, this hot water rises and cooler water moves down to replace it, causing a circular motion. Radiator - Puts warm air out at the top and draws in cooler air at the bottom.
Not sure if it’s right tho!
I do believe that the answer is D.
Hope this is right! Have a great day! :-)
Answer:
The force that is exerted when a shopping cart is pushed is a type of push force, supplied by the muscles of the cart pusher's body.
The forces that causes a metal ball to move toward a magnet is a type of pull force that is as a result of the magnetic field forces.
Explanation:
Forces are divided into push forces that tends to accelerate a body away from the source of the force, and pull forces that accelerates the body towards the force source.
Examples of push forces includes pushing a cart, pushing a table, repulsion of two similar poles of a magnet etc. Examples of pull forces includes a attractive force between two dissimilar poles of a magnet, pulling a load by a rope, a dog pulling on a leash etc.
Our data are,
State 1:

State 2:

We know as well that 
To find the mass we apply the ideal gas formula, which is given by

Re-arrange for m,

Because of the pressure, temperature and volume ratio of state 1 and 2, we have to

Replacing,

For conservative energy we have, (Cv = 0.718)
