Write 25 times 10 to the 6 power in scientific notation

A model rocket is launched directly upward at a speed of 28 meters per second from a height of 12 meters. The function f(t) = -

Jet001 [13]

Answer:

6.11 seconds

Step-by-step explanation:

Given

$f(t) = -4.9t^2 + 28t + 12$

Required

When will it hit the ground?

When it hits the ground, f(t) = 0.

So, we have:

$0 = -4.9t^2 + 28t + 12$

Solve quadratic equation using formula

$t = \frac{-b \± \sqrt{b^2 - 4ac}}{2a}$

$t = \frac{-28 \± \sqrt{28^2 - 4*-4.9*12}}{2*-4.9}$

$t = \frac{-28 \± \sqrt{1019.2}}{-9.8}$

$t = \frac{-28 \± 31.92}{-9.8}$

Split

$t = \frac{-28 + 31.92}{-9.8}$ or $t = \frac{-28 - 31.92}{-9.8}$

$t = \frac{3.92}{-9.8}$ or $t = \frac{-59.92}{-9.8}$

$t = -0.4$ or $t = 6.11$

Time can not be negative. So:

$t = 6.11$

6 0

3 years ago

Write an expression for the calculation subtract the difference of 20 and 13 from 70.

irakobra [83]

So subtract the diffference of 20 and 13 from 70
so first we find the difference and then subtract that from 70
use parenthases so
difference of 20 and 13 is equal to (20-13)
subtract that from 70
70-(20-13)
so you would do the pemdas and get 7 for the inside parethasees then do
70-7=63

equation is 70-(20-13)

8 0

3 years ago

Read 2 more answers

Pliz help me with this. y=3x/5+2:X

mezya [45]

Answer:

sorry I don't know.....:)

8 0

3 years ago

24 red flowers and 18 white flowers will be equally divided into groups. Find the greatest number of groups that can be created

mariarad [96]

Given:

The number of red flowers =24

The number of white flowers = 18

As flowers divided equally.

$\begin{gathered} 24=4\times6 \\ 18=3\times6 \end{gathered}$

The HCF ( highest common factor) of 24 and 18 is 6.

The largest number of group that can be created is 6.

4 0

1 year ago

A chemical plant has an emergency alarm system. When an emergency situation exists, the alarm sounds with probability 0.95. When

Lapatulllka [165]

Answer:

6.56% probability that a real emergency situation exists.

Step-by-step explanation:

We have these following probabilities:

A 0.4% probability that a real emergency situation exists.

A 99.6% probability that a real emergency situation does not exist.

If an emergency situation exists, a 95% probability that the alarm sounds.

If an emergency situation does not exist, a 2% probability that the alarm sounds.

The problem can be formulated as the following question:

What is the probability of B happening, knowing that A has happened.

It can be calculated by the following formula

$P = \frac{P(B).P(A/B)}{P(A)}$

Where P(B) is the probability of B happening, P(A/B) is the probability of A happening knowing that B happened and P(A) is the probability of A happening.

In this problem:

What is the probability of a real emergency situation existing, given that the alarm has sounded.

P(B) is the probability of there being a real emergency situation. So $P(B) = 0.004$ .

P(A/B) is the probability of the alarm sounding when there is a real emergency situation. So P(A/B) = 0.95.

P(A) is the probability of the alarm sounding. This is 95% of 0.4%(real emergency situation) and 2% of 99.6%(no real emergency situation). So

P(A) = 0.95*0.04 + 0.02*0.996 = 0.05792

Given that the alarm has just sounded, what is the probability that a real emergency situation exists?

$P = \frac{P(B).P(A/B)}{P(A)} = \frac{0.004*0.95}{0.05792} = 0.0656$

6.56% probability that a real emergency situation exists.

6 0

3 years ago