2. the equation h(t)=−16t2+19t+110 gives the height of a rock, in feet, t seconds after it is thrown from a cliff. what is the initial velocity when the rock is thrown?

For this case we have an equation of the form:
 h (t) = - (1/2) * a * t ^ 2 + vo * t + h0
 Where,
 vo: initial speed
 a: acceleration:
 h0: initial height.
 We have the following equation:
 h (t) = - 16t2 + 19t + 110
 Therefore, the initial velocity is:
 vo = 19 feet / s
 
 The initial velocity when the rock is thrown:
 vo = 19 feet / s