Answer:
![1) X(t)=Xo+So(t)+(1)/(2) g(t)^(2)](https://img.qammunity.org/2020/formulas/physics/high-school/uqtjuxl8q9cz91cxnum8s51e8sjlowbe3t.png)
2) S(Δt)=So+g(Δt)
Step-by-step explanation:
I think the equation they gave you for the Height upon time in seconds it's (1), where if you see, you will find the gravity, that you should multiply by 2 because, its divided by two in (1) (that should be your (a)), then, once you find your gravity, you can use the equation (2) to know the Final Speed replacing g , at the time asked, remember that g is gravity, and Δt is the: final time- initial time.
so in the [1,2] interval of time, your Δt=1s, and in [1,1.5] is Δt=0,5s.
i hoped it helped you even though i cant give you the exact answer right now.