Math help needed

[Donald No.4383717]

if a rock falls form a height of 49 meters on Earth, the height H (in meters) after x seconds is approximately H(x)=49-4.9x^2

When is the height of the rock 5 meters?

When does the rock strike the ground?

Round to 3 decimals places as needed


I have forgotten on how to do this.

please help

[Anonymous No.4383722]

1. If the height is 5 meters, then 5 = 49-4.9x^2. Solve for x.
2. The rock strikes the ground when the height = 0; that is, when 49-4.9x^2 = 0. Solve for x.

We did these in Algebra 1. How old are you?

[Donald No.4383724]

its been 6 years since since I took math and this is my review for taking math 151

[Anonymuos No.4383737]

shouldn't a=9.8m/s^2 not 4.9

[Anonymous No.4383757]

>>4383737
1/2mv^2 bro.

[Donald No.4383886]

ok thank you, i got the correct answer.

Thank you again.

[Anonymous No.4383956]

math 151 is calculus right? You should not take this class... you will fail if you cant do algebra. i don't intend any offense i only intend to save you from a devastating failure

[Anonymuos No.4383967]

>>4383757
that's kinetic energy. Not acceleration under constant force in a frictionless vacuum.