Forces that are equal in size but opposite in direction and do not cause a change in an object's movement are called balanced forces.
forces that aren't equal in size and do cause a change in movement (what it seems like you're asking for) are called UNBALANCED FORCES
so answer (in case that wasn't clear, as I'm tired) : unbalanced forces
Once the car is on top of the hill it contains potential energy witch means it is storing enough energy to slide the hill until acted on. Once the car moves and slides down the hill it creates kinetic energy witch means it's in motion. The car then turns the kinetic energy into mechanical energy witch means it's working. I'm not sure if that helped but good luck!
Convection is the transfer of heat from one place to another via the movement of fluids. It happens from higher energy level to lower energy level to bring equilibrium to the system.
For vertical set up , if the hot water is places on top of cold water, direction of convection will be from top to bottom. So, gravity can play a role in increasing the rate of flow of energy. if the cold water is places on top of hot water, direction of convection will be from bottom to top. So, gravity can play a role in decreasing the rate of flow of energy.
for Horizontal set up, when hot and cold water are placed side by side, gravity will not playing a role in the flow of energy.So, the position of hot or cold water would not matter.
The answer would be Kelvin which is written as K
In short, Your Answer would be Option D
Hope this helps!
