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

i think its

0.19 m/s and 0.45 m/s