Part a consider another special case in which the inclined plane is vertical (θ=π/2). in this case, for what value of m1 would the acceleration of the two blocks be equal to zero?

The answer would be m1 = m2

FBD of m1 is the sum of the forces in the y direction = 0 
0 = T - m1*g 
transposing:
m1*g = T 

FBD of m2 is the sum of the forces in the y direction = 0 
0 = T - m2*g 
transposing:
m2*g = T 

set them equal to each other and solve for m1 
m1*g = m2*g

= m1 = m2

Explanation:

The force on individual mass would be downwards or descending and equal to the tension shaped by the other mass, which would be upward or rising by the act of the seamless pulley, so the forces cancel on each mass.

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.