Susan and hannah are each riding a swing. susan has a mass of 25 kilograms, and hannah has a mass of 30 kilograms. susan’s swing moves with a velocity of 10 meters/second, while hannah’s swing moves with a velocity of 8.5 meters/second. susan’s kinetic energy is (1080,1250,1350, or 1500) joules. susan’s kinetic energy is greater than hannah’s because: speed has a greater effect than mass, mass has a greater effect than speed, mass and speed have the same effect, or mass and speed dont have any effect?

Kinetic energy is given by:

K.E. = 0.5 m v²

Susan has mass, m = 25 kg

Velocity with which Susan moves is, v = 10 m/s

Hannah has mass, m' = 30 kg

Velocity with which Hannah moves is, v' = 8.5 m/s

Kinetic energy of Susan:

0.5 m v² = 0.5 × 25 kg × (10 m/s)² = 1250 J

Kinetic energy of Hannah:

0.5 m v'² = 0.5 × 30 kg × (8.5 m/s)² = 1083.75 J

Susan's kinetic energy is 1250 J and Hannah's kinetic energy is 1083.75 J.

Since kinetic energy is dependent on mass and square of speed. Thus, speed has a greater effect than mass. As it is evident from the above example. Susan has greater kinetic energy due to higher speed than Hannah.

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.

a and b sometimes have a positive value