Answer:
a) Δd=v₂Δt+[tex]\frac {1}{2}[/tex]aΔt²
v₂=0 (hits ground)
Δd=[tex]\frac {1}{2}[/tex]aΔt²
Δt²=Δd÷[tex]\frac {1}{2}[/tex]a
t=√25÷[tex]\frac {1}{2}[/tex](9.8) 9.8m/s²=gravity
t=5÷4.8
t=1.04s
b) a=[tex]\frac{v_2-v_{1} }{t}[/tex]
a×t=v₂-v₁
v₂=(a×t)+v₁
v₂=(9.8×1.04)+20
v₂=10.192 + 20
v₂=30.192
v₂=30.2m/s rounded
