A car is stopped at a red light. When the light turns green, it increases its speed to 45miles/hour in 15 seconds. What is the car acceleration?

Acceleration = 3 miles per sec²

Explanation:

A car is stopped at a red light that means speed of the car 'u' = 0

As the light turns green, speed of the car increases from 0 to 45 miles per hour,

v = 45 miles per hour

Duration for the increase in speed from 0 to 45 miles per hour is,

t = 15 seconds

By using formula to calculate the acceleration,

v = u + at

45 = 0 + a×15

a =

  = 3 miles per sec²

Therefore, acceleration of the car is 3 miles per sec².

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.