A ball is thrown from a height of 25 meters with an initial downward velocity of 5/ms. The ball's height h (in meters) after t seconds is given by the following.

h=25-5t-5t^2

How long after the ball is thrown does it hit the ground?

Round your answer (s) to the nearest hundredth.

Question

Macie Carter

Mathematics

1 April, 19:15

A ball is thrown from a height of 25 meters with an initial downward velocity of 5/ms. The ball's height h (in meters) after t seconds is given by the following.

h=25-5t-5t^2

How long after the ball is thrown does it hit the ground?

Round your answer (s) to the nearest hundredth.

+5

Answers (1)

Know the Answer?

Nikhil · Answer 1

The ball hits the ground when h=0, 5 (5-t-t²) = 0.

t²+t-5=0. t²+t=5, t²+t+¼=5¼, (t+½) ²=5¼.

t+½=±√ (21/4) = ±√21/2=±4.5826/2=±2.2913.

So t=-0.5 ±2.2913. We reject the negative solution because t starts from zero so negative values are out of range. Therefore t=1.79 seconds.

A ball is thrown from a height of 25 meters with an initial downward velocity of 5/ms. The ball's height h (in meters) after t seconds is given by the following.h=25-5t-5t^2How long after the ball is thrown does it hit the ground?Round your answer (s) to the nearest hundredth.

A ball is thrown from a height of 25 meters with an initial downward velocity of 5/ms. The ball's height h (in meters) after t seconds is given by the following.

h=25-5t-5t^2

How long after the ball is thrown does it hit the ground?

Round your answer (s) to the nearest hundredth.