Question

Algebra 2 help?!?!?!

The height h in feet of a baseball on Earth after t seconds can be modeled by the function h(t) = -16(t - 1.5)2 + 36, where -16 is a constant in ft/s2 due to Earth's gravity. The gravity on Mars is only 0.38 times that on Earth. If the same baseball were thrown on Mars, it would reach a maximum height 59 feet higher and 2.5 seconds later than on Earth. Write a height function for the baseball thrown on Mars.

Help? Now sure how to adjust the equasion...

Answer 1

Would it be just making it -16t^2+24+30=0 turned into y = -6.08(t - 4)2 + 95 by multiplying by 0.38?

Answer 2

looks good

Answer 3

I would do the problem by noticing the vertex on earth is (1.5,36)
the vertex on mars will be (1.5+2.5, 36+59) or (4,95)
the -16 coefficient on earth gets changed to -16*0.38= -6.08
so in vertex form, plugging in the numbers for (h,k) and a in
y= a(x-h)^2 + k
y= -6.08(t-4)^2 + 95

Answer 4

ok, great so I did it right? so will my way of just multiplying each thing by 0.38 work all the time or was this just a fluke?

Answer 5

good question.

Answer 6

the earth's equation comes from physics, and starts with earth's force due to gravity... so your trick probably works for this situation. But if the equation were some random parabola, I don't think it works. I think they expect you to solve it the way I did.

Answer 7

Oh, ok I'll copy and paste your comment to a word where I can use it as an example then! THANKS!! AGAIN!!!

Answer 8

can you explain what you did in more detail ?

Answer 9

I took the original equasion (h(t) = -16(t - 1.5)^2 + 36) and multiplied each section by 0.38 (h(t) = -16x0.38 (t - 1.5x0.38)^2 + 36 to get y = -6.08(t - 4)^2 + 95 as the only option that had both of the first two right, not sure how I got from 36 to 95, my notes are beyond sloppy but I did it some how...

Answer 10

ok, in that case, the only thing you should multiply by 0.38 is the -16.
you "tweak" the 1.5 and the 36 by adding the numbers they told you.

Answer 11

oh ok so 2.5 s longer and 59 ft higher gets added there?

Answer 12

yes