Wednesday

October 22, 2014

October 22, 2014

Posted by **gagan** on Friday, January 23, 2009 at 9:21am.

h = —4.9t^2 + 27t + 2.4

a)How high is the balloon after 1 s?

b)For how long is the balloon more than 30 m high?

c)What is the maximum height reached by the balloon?

d)When will the balloon hit the ground?

Can you please help me thanks and need this urgently plz plz plz plz and thanks a lot for doing this.

- math -
**Reiny**, Friday, January 23, 2009 at 9:31ama) just sub t=1 into the function

b) set -4.9t^2 + 27t + 2.4 = 30

and solve. You should get two solution for t

The balloon will be above 30 m for all values of t between those two solutions

c) find the vertex, the max height is the h coordinate of the vertex

Use this method:

for y = ax^2 + bx + c, the x of the vertex is -b/(2a)

once you have that value, sub it back in to get the y.

(of course you are dealing with t instead of x, and h instead of y)

d) set —4.9t^2 + 27t + 2.4 = 0 and solve for t

One of the values of t will be negative, that would be an extraneous root.

- math -
**gagan**, Friday, January 23, 2009 at 9:41amthnx a lot now i fully understand

**Answer this Question**

**Related Questions**

Math - A water balloon is shot into the air so that its height h, in metres, ...

Math Grade 11 U - A water balloon is catapulted into the air so that its height...

Math/calculus - a toy rocket is shot into the air at the top of a building so ...

physics - a hot-air balloon having initial velocity vi as it ascends. Then, a ...

math - a rock is thrown straight up in the air from an initial height of ho, in...

algebra - an arrow is shot into the air with an initial velocity of 96 feet per ...

physics - Others say that the balloon was 23 metres high and 14 metres wide. ...

Algebra 2 - Damon thank you for the previous help. A geyser sends a blast of ...

math - really need help, i have no idea how to answer this question ! A stone ...

math - really need help, i have no idea how to answer this question ! A stone ...