Ask question

Ask question

All categories

3 years ago

14

A rock is dropped from a height of 25 feet. The function h=-16t^2 +25 gives the height h of the rock after t seconds. When does

it hit the ground?

1 answer:

scZoUnD [109]3 years ago

3 0

Answer:

5 seconds

Step-by-step explanation:

The ground is 25 eet, so 25=-16t^2+400

-16t^2=-400, 16t^2=400

t^2=25, dividing both sides by 16

t=5 seconds.

You might be interested in

The probability of being a universal donor is 6% (O-negative-blood type). Suppose that 6 people come to a blood drive.' a) What

Tcecarenko [31]

Answer:

$Mean = 0.36$

$SD = 0.5817$

$P(x=3) = 0.003588$

Step-by-step explanation:

Given

Let

A = Event of being a universal donor.

So:

$P(A) = 0.06$

$n = 6$

Solving (a): Mean and Standard deviation.

The mean is:

$Mean = np$

$Mean = 6 * 0.06$

$Mean = 0.36$

The standard deviation is:

$SD = \sqrt{np(1-p)}$

$SD = \sqrt{6*0.06*(1-0.06)}$

$SD = \sqrt{0.3384}$

$SD = 0.5817$

Solving (b): P(x = 3)

The event is a binomial event an dthe probability is calculated as:

$P(x) = ^nC_x * p^x * (1-p)^{n-x}$

So, we have:

$P(x=3) = ^6C_3 * 0.06^3 * (1-0.06)^{6-3}$

$P(x=3) = ^6C_3 * 0.06^3 * (1-0.06)^3$

$P(x=3) = 20 * 0.06^3 * (1-0.06)^3$

$P(x=3) = 0.003588$

7 0

2 years ago

What type of object is pictured below?

EleoNora [17]

Answer:

ray

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

Simplify the following

ZanzabumX [31]

Answer:

28∛3+72

Step-by-step explanation:

distribute: 28∛3+24∛3∛9 - be careful, ∛9 is not equal to 3! You are looking for three "copies" of a number since it is a ∛ not √.

28∛3+24∛(3*9)=28∛3+24*3 = 28∛3+72

5 0

2 years ago

Help!! Which of the following represents a rotation

Neporo4naja [7]

Another test question. whyyy

Answer is the last one because look at the new coordinates shown in blue.

4 0

2 years ago

Help Brian and Chris went together to Target to find party favors for a birthday party they are throwing together.

rusak2 [61]

(a) Let x be the cost of one of Brian's items, then cost of all 4 items bought by Brian will be 4x.

We have been given that Chris bought 3 items that each cost $2.50 more than Brian’s items each cost. The price of each item bought by Chris will be x+2.5. Therefore, the cost of all 3 items bought by Chris will be $3(x+2.5)$ .

(b) We are told that Brian and Chris both paid the same amount of money, so we can equate costs of Brian's 4 items and Chris's 3 items as:

$4x=3(x+2.5)$

Now let us solve for x by distributing 3.

$4x=3x+7.5$

$4x-3x=7.5$

$x=7.5$

Therefore, cost of Brian's each item is $7.5.

Now let us find price of Chris's each item.

$\text{Cost of Chris's each item}=x+2.5=7.5+2.5=10$

Therefore, cost of Chris's each item is $10.

(c) Now let us check our solution by substituting x=7.5 in $4x=3(x+2.5)$ .

$4(7.5)=3(7.5+2.5)$

$4(7.5)=3(10)$

$30=30$

We can see that both Brian and Chris spent equal amount of money that is $30, therefore, our solution is correct.

5 0

3 years ago