Answer:
v_{B} = 15.03 ft / s
Explanation:
For this exercise let's use the accelerated motion relationships in one dimension
v = vo + a t
a = (v- v₀) /a
a = (19.4 -12.4) /4.00
a = 1.75 ft / s²
As we have the acceleration let's look for the speed for the time of 1.50 s
[tex]v_{B}[/tex] = vo + a t
v_{B} = 12.4 + 1.75 1.50
v_{B} = 15.03 ft / s