A Coin Is Tossed Upward from a Balcony 390 $h ( t ) = - 16 t ^ { 2 } + v _ { 0 } t + h 0$

Multiple Choice

A coin is tossed upward from a balcony 390 ft high (h₀) with an initial velocity (v₀) of 16 ft/sec , according to the formula $h ( t ) = - 16 t ^ { 2 } + v _ { 0 } t + h 0$ . where t is time in seconds. During what interval of time will the coin be at a height of at least 70 ft ?

A) $4 \sec \leq t \leq 5 \mathrm { sec }$
B) $0 \mathrm { sec } \leq \mathrm { t } \leq 5 \mathrm { sec }$
C) $5 \mathrm { sec } \leq \mathrm { t } \leq 10 \mathrm { sec }$
D) $0 \sec \leq t \leq 1 \mathrm { sec }$