The student quickly discovers that placing the marshmallow over the flame is more effective than heating the marshmallow on the side of the flame. According to the information above, what type of heat transfer is present when the marshmallow is above the fire that is not present when the marshmallow is on the side of the fire

The answer is convection.

Explanation:

There are three types of heat transfer: conduction, convection and radiation.

So in this case, when the marshmallow is above the fire, it is exposed to convection, which does not occur when it is on the side of the fire.

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.

real, smaller and upside-down.   so the answer should be b.