What situation primarily involves heat transfer by convection?

Explanation:

In the process of convection, first the molecules of substance gets heat and becomes heated. As the molecules heated, their density decreases and hence they rises up. And the molecules which are cooler, they fall and comes in contact of higher temperature and then they rises up. the process repeats itself until the entire liquid heated uniformly.

Heating of a fluid bulk from the bottom.

Explanation:

Whenever a fluid bulk is heated form the lower layers then due to the variation of the density of the fluid at different temperature we observe the movement of molecules leading to convection.

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles