The velocity when t = 1 is 10ft/s.
Given that,
Based on the above information, the velocity should be
v(t)=dy(t) ÷ dt
= d(42t - 16t^2) ÷ dt
= 42 - 32t
Since t=1
So, the velocity should be
v = 42 - 32 × 1
= 10ft/s
Therefore we can conclude that the velocity when t = 1 is 10ft/s.
Learn more: brainly.com/question/13639113