Ask question

Ask question

All categories

2 years ago

11

A model rocket is launched from a platform 12 meters high at a speed of 35 meters per second. Its height h can be modeled by the

equation h= -4.9t'2+35t+12 where t is the time in seconds. at what time will the rocket be altitude of 60 meters.

1 answer:

babymother [125]2 years ago

6 0

Answer:

Step-by-step explanation:

so set the given equation equal to 60 and solve for t

60= -4.9 $t^{2}$ +35t +12

0= -4.9 $t^{2}$ +35t - 48

now use the quadratic equation to solve for t

-b +- sq rt ( $b^{2}$ - 4 a c ) / 2 a

t = -35 +- sq. rt [ 1225 -4(-4.9)(-48) ] / 2 (-4.9)

t = -35 +- sq. rt [ 284.2] / -9.8

t = -35 +- 16/858 / - 9.8

t = 3.571 +- 1.72

t = 1.85 seconds ( on the way up ) or t = 5.29 seconds ( on the way down)

at both of those times the rocket will be at 60 meters :)

You might be interested in

Y=-1/3x^2-4x-5 in vertex form

grigory [225]

Answer:

$Y=-\frac{1}{3}(x+6)^2+7$ [Vertex form]

Step-by-step explanation:

Given function:

$Y=-\frac{1}{3}x^2-4x-5$

We need to find the vertex form which is.,

$y=a(x-h)^2+k$

where $(h,k)$ represents the co-ordinates of vertex.

We apply completing square method to do so.

We have

$Y=-\frac{1}{3}x^2-4x-5$

First of all we make sure that the leading co-efficient is =1.

In order to make the leading co-efficient is =1, we multiply each term with -3.

$-3\times Y=-3\times\frac{1}{3}x^2-(-3)\times4x-(-3)\times 5$

$-3Y=x^2+12x+15$

Isolating $x^2$ and $x$ terms on one side.

Subtracting both sides by 15.

$-3Y-15=x^2+12x-15-15$

$-3Y-15=x^2+12x$

In order to make the right side a perfect square trinomial, we will take half of the co-efficient of $x$ term, square it and add it both sides side.

square of half of the co-efficient of $x$ term = $(\frac{1}{2}\times 12)^2=(6)^2=36$

Adding 36 to both sides.

$-3Y-15+36=x^2+12x+36$

$-3Y+21=x^2+12x+36$

Since $x^2+12x+36$ is a perfect square of $(x+6)$ , so, we can write as:

$-3Y+21=(x+6)^2$

Subtracting 21 to both sides:

$-3Y+21-21=(x+6)^2-21$

$-3Y=(x+6)^2-21$

Dividing both sides by -3.

$\frac{-3Y}{-3}=\frac{(x+6)^2}{-3}-\frac{21}{-3}$

$Y=-\frac{1}{3}(x+6)^2+7$ [Vertex form]

8 0

3 years ago

30 points!!! Plzz help!!! Will give Brainliest!!!! Need help ASAP!!!!

Vesnalui [34]

B. Right (they are 90° angles)
D. Adjacent (they share sides)
G. Supplementary (the total of the 2 angles is 180°)

7 0

3 years ago

Read 2 more answers

In a freshman class of 80 students,22 students take Consumer Education,20 students take French,and 4 students take both.Which eq

MAXImum [283]

<h3>Answer: Choice C</h3>

P = 11/40 + 1/4 - 1/20

=========================================================

Explanation:

The formula we use is

P(A or B) = P(A) + P(B) - P(A and B)

In this case,

P(A) = 22/80 = 11/40 = probability of picking someone from consumer education
P(B) = 20/80 = 1/4 = probability of picking someone taking French
P(A and B) = 4/80 = 1/20 = probability of picking someone taking both classes

So,

P(A or B) = P(A) + P(B) - P(A and B)

P(A or B) = 11/40 + 1/4 - 1/20

which is why choice C is the answer

----------------

Note: P(A and B) = 1/20 which is nonzero, so events A and B are not mutually exclusive.

6 0

2 years ago

Bella works at a shoe store. In addition to a fixed salary, she earns a commission for each pair of shoes that she sells. The ta

xxTIMURxx [149]

D. It Is The Most Fitting Answer. The Other 3 Equal More Than Needed.

7 0

2 years ago

Find the product of z1 and z2, where z1 = 5(cos 60° + i sin 60°) and z2 = 7(cos 210° + i sin 210°)

Verizon [17]

Answer:

cos210=cos(180+30)=−cos30=−√32 . sin210=sin(180+30)=−sin30=−12 . 3(cos210+isin210) =3(−√32)+3i(−12). −(32)√3−(32)i. My favourite way of seeing that sin30=12 and cos30=√32 is ...

Step-by-step explanation:

But that's what I say personally

3 0

2 years ago