Question

A ball is thrown into the air. The function h=10t-5t^2 can be used to find the height(h) of the ball in meters after t seconds. How long does it take for the ball to reach a height of 5 meters?

Answer 1

Answer: It will take 1 second for the ball to reach a height of 5 meters.

Explanation:

Given: The function
`h=10t-5t^2` can be used to find the height(h) of the ball in meters after t seconds.

Now, put h= 5 meters, we get

`5=10t-5t^2`

`\Rightarrow\ 1=2t-t^2\ \ \[\text{divide both sides by 5}]\\\\\Rightarrow\ t^2-2t+1=0\\\\\Rightarrow(t-1)^2=0\\\\\Rightarrow (t-1)=0\\\\\Rightarrow t=1`

Hence, it will take 1 second for the ball to reach a height of 5 meters.