Question

La velocidad de un automóvil es de 45 km / h cuando el conductor golpea el freno produciendo una aceleración negativa de 4.3 m / s2, determine la distancia recorrida antes de que se detenga por completo.

Answer 1

x = 18.16 m

Step-by-step explanation:

To find the distance traveled by the car you use the following kinematic formula for a negative acceleration:

`v^2=v_o^2-2ax` (1)

v: final velocity = 0m/s (because the car stops)

vo: initial velocity = 45 km/h = 45(1000m)/(3600s) = 12.5 m/s

a: acceleration = 4.3m/s^2

x: distance = ?

you do "x" the subject of the formula (1), and the replace the values of the other parameters in order to calculate x:

`x=(v_o^2-v^2)/(2a)\\\\x=((12.5m/s)^2-(0m/s)^2)/(2(4.3m/s^2))\\\\x=18.16m`

hence, the distance traveled is 18.16 m