2.- Un móvil viaja en línea recta y acelera
apenas pasa el punto origen de
coordenadas. Su aceleración es constante
de 4 m/s
2
. En t=0 s, está a 5m del origen
moviéndose hacia +x a razón de 15 m/s.
Determine:
a) Su velocidad luego de 2 s.
b) Su posición donde logra una velocidad
de 25 m/s.

a) 23 m/s

b) 43 m

Explanation:

a)

To find the velocity at t = 2s you use the following formula:

  (1)

a: acceleration = a = 4m/s^2

t: time = 2s

vo: initial velocity = 15m/s (for x = 5m)

you replace the values of t and a in the equation (1):

b)

The position in which the velocity is 25m/s can be calculated by the following formula:

This is the position for an initial speed of 15m/s. The position of the object from the origin is the sum of the last result with the initial position, that is:

hence, the position is 43 m from the origin

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.

explanation:

as the height from which the ruler was dropped increased, the speed of the ruler at ryan's hand increased.