Answer:
 a) v= 2.1 m/s
 b) ω = 0.807 rad/s
Step-by-step explanation
Conceptual analysis : 
The dog and the merry-go- round describes a circular motion, then, the following formulas apply :
  Formula (1)
v = ω *r Formula (2)
Where:
 : Centripetal acceleration(m/s²)
v: linear speed or tangential (m/s)
r : radius of the circle (m)
ω : angular speed ( rad/s)
Data
r= 2.6 m
 = 1.7 m/s²
Problem develpment
a) We replace data in the formula 1 to calculate the dog's linear speed(v): 
 
 


v= 2.1 m/s
 b)We replace data in the formula 2 to calculate the angular speed of the merry-go- round (ω). 
v = ω *r
2.1 = ω *2.6
ω = 2.1/2.6
ω = 0.807 rad/s