In 1-rescuer bls for a child with unwitnessed cardiac arrest, activation of the emergency response system occurs and the compression-to-ventilation ratio

Immediately

30:2

Explanation:

The BLS responsive system for a child with unwitnessed cardiac arrest  include the following  

a)As the first step the rescuer must check for the safety at site.  

b)Rescuer must check for the responsiveness of the patient and if the patient is unresponsive nearby help must be seek by shouting.  

c)Emergency response must be activated immediately through mobile phones  

d)Pulse must be checked and in case if the breathing is normal then the patient must be monitored till the emergency response system arrives. In case if breathing is absent or slow CPR cycles must be begin in the ratio 30 compression and 2 breaths

acceleration= v2-v1/t so 8m/s-3m/s / 3s =to 8/3 or

2.67 m/s^2

hope i

-lavira: )

i won't lie i don't know so go online and ask google thats what i do