How to do arrays in repeated halving

A bullet is fired straight up from a gun with initial velocity 1120 feet per second at an initial height of 8 feet. Use the form

Dafna1 [17]

Answer:

70 seconds

Step-by-step explanation:

Given that;

The initial velocity $v_o$ of the bullet fired = 1120 ft/s

Initial height h = 8 feet

The expression to determine how many seconds it takes the bullet to hit the ground is:

$h = -16t^2 +v_ot + 8$

Thus;

Replacing the value of $v_o$ = 1120 and h = 0 (i.e. when h =0) in the above expression; we have:

$0= -16t^2 +(1120)t + 8$

$= -16t^2 +(1120)t + (8-0)$

= -16t² + 1120t + 8

mulitiply through by (-)

= 16t² -1120t - 8

Divide through by 8

= 2t² - 140t - 1

The above expression forms a quadratic equation.

where;

a = 2

b = -140

c = - 1

So, by using the quadratic formula $\dfrac{-b \pm \sqrt{b^2-4ac}}{2a}$ , we have:

$= \dfrac{-(-140) \pm \sqrt{(-140)^2-4(2)(-1)}}{2(2)}$

$= \dfrac{140 \pm \sqrt{19600-(-8)}}{4}$

$= \dfrac{140 \pm \sqrt{19608}}{4}$

$= \dfrac{140 \pm 140}{4}$

$=\dfrac{140+ 140}{4} \ \ \ OR \ \ \ \dfrac{140-140}{4}$

$=\dfrac{280}{4} \ \ \ OR \ \ \ 0$

= 70

Thus, the time (in seconds) it took the bullet to it the ground = 70 seconds

6 0

2 years ago

What is the slope of the line that passes through the points listed in the table?

Allisa [31]

Answer:

D. -4

Step-by-step explanation:

the slope formula is

m=(y2-y1)/(x2-x1)

(x2,y2) = (4,7)

(x1, y1) = (5,3)

So (7-3)/(4-5) = 4/-1 = -4

4 0

2 years ago

Give an example of a time when finding the percentage of a number would be useful. Explain.

kupik [55]

When you're out shopping and something you want to buy is on sale. You can take the original price and give it's percentage to find out how much it really is.

4 0

3 years ago

On a unit circle, the terminal point of 0 is (sqrt3/2,1/2) What is 0?

san4es73 [151]

Answer:

The measure of $\theta$ is 30°.

Step-by-step explanation:

In the statement, the angle has been misrepresented. The corrected statement is described below:

"On a unit circle, the terminal point of $\theta$ is $\left(\frac{\sqrt{3}}{2}, \frac{1}{2} \right)$ . What is $\theta$ ?"

The measure of the angle ( $\theta$ ), in radians, is in standard form, that is, it is done with respect to the +x semiaxis. The measure of the angle whose terminal point is of the form $(x,y)$ is determined by the following inverse trigonometric function: