Solve.
-A ball is thrown upward with an initial velocity of 21 meters per second from a cliff that is 70 meters high. The height of the ball is given by the quadratic equation $h = - 4.9 t ^ { 2 } + 21 t + 110$ where $\mathrm { h }$ is in meters and $\mathrm { t }$ is the time in seconds since the ball was thrown. Find the time that the ball will be 40 meters from the ground. Round your answer to the nearest tenth of a second.
A) $7.3 \mathrm { sec }$
B) $7.4 \mathrm { sec }$
C) $6.6 \mathrm { sec }$
D) $6.5 \mathrm { sec }$

Question

Quizplus · Accepted Answer

The Answer of Solve.
-A ball is thrown upward with an initial velocity of 21 meters per second from a cliff that is 70 meters high. The height of the ball is given by the quadratic equation $h = - 4.9 t ^ { 2 } + 21 t + 110$ where $\mathrm { h }$ is in meters and $\mathrm { t }$ is the time in seconds since the ball was thrown. Find the time that the ball will be 40 meters from the ground. Round your answer to the nearest tenth of a second.
A) $7.3 \mathrm { sec }$
B) $7.4 \mathrm { sec }$
C) $6.6 \mathrm { sec }$
D) $6.5 \mathrm { sec }$

Solve -A Ball Is Thrown Upward with an Initial Velocity h=−4.9t2+21t+110h = - 4.9 t ^ { 2 } + 21 t + 110h=−4.9t2+21t+110

Solve
-A Ball Is Thrown Upward with an Initial Velocity $h = - 4.9 t ^ { 2 } + 21 t + 110$