What does 7×42 equal

17.

Marta_Voda [28]

Answer:

a) 50 meters

b) 2354 meters

c) 12 seconds

d) 24.13 seconds

Step-by-step explanation:

Hello!

<h3>a) How far is Lincoln above the ground when he shoots the gun?</h3>

We need to really understand what the variables represent in this question. Given that t is time, and h is height, the time at which he shoots the bullet will be 0, as the bullet hasn't started traveling yet. This means that we can solve for the original height of the bullet by plugging in 0 for time in the equation.

Equation: $h = -16t^2 + 384t + 50$

Plug in 0 for t:

$h = -16t^2 + 384t + 50$
$h = -16(0)^2 + 384(0) + 50$
$h = 50$

The height at which Lincoln shot the bullet is 50 meters.

We can also look at this graphically. The height of origin will simply be when the x-value (in this case t-value) is 0. That means it is the point at which the graph intersects the y-axis, known as the y-intercept.

Standard form of a Parabola: $y = ax^2 + bx + c$

The y-intercept is the "c" value.

Given our equation: $h = -16t^2 + 384t + 50$

The c-value is 50. This proves that the y-intercept is 50.

<h3 /><h3>b)How high does the bullet travel vertically relative to the ground?</h3>

We want to find the highest point of the graph. To do that, we can find the vertex.

We can utilize the Axis of Symmetry (AOS) to find the Vertex.

First, find the AOS using the formula: $AOS = -\frac{b}{2a}$

a = -16
b = 384

Plug it into the formula:

$AOS = -\frac{b}{2a}$
$AOS = -\frac{384}{2(-16)}$
$AOS = \frac{384}{32}$
$AOS = 12$

Plug in 12 for t in the equation:

$h = -16t^2 + 384t + 50$
$h = -16(12)^2 + 384(12) + 50$
$h = -2304 + 4608 + 50$
$h = 2304+50$
$h = 2354$

Therefore, the highest point of the bullet is 2354 meters.

<h3>c)How long does it take the bullet to reach its greatest height?</h3>

We answered this in the last question. The t-value when h is at its highest is 12.

<h3>d)After how many seconds (round to nearest 100th) does the bullet hit the ground?</h3>

We have to solve for the values of t when h is 0 (when it touches the ground).

Set the equation to 0, and solve using the quadratic formula.

Quadratic formula: $x = \frac{-b\pm\sqrt{b^2 - 4ac}}{2a}$

$x = \frac{-b\pm\sqrt{b^2 - 4ac}}{2a}$
$x = \frac{-384\pm\sqrt{384^2 - 4(-16)(50)}}{2(-16)}$
$x = \frac{-384\pm\sqrt{147456 +3200}}{-32}$
$x = \frac{-384\pm\sqrt{150656}}{-32}$
$x = \frac{-384\pm388.14}{-32}$
$x = -\frac{4.14}{32}, x = \frac{772.14}{32}$

We are only going to take the positive solution, as we can't have a negative time. The solution that doesn't work is called an extraneous solution.

$x = \frac{772.14}{32}$
$x = 24.13$

It takes approximately 24.13 seconds for the bullet to hit the ground.

6 0

2 years ago

The total number of restaurant-purchased meals that the average person will eat in a restaurant, in a car, or at home in a ye

zloy xaker [14]

Answer:

Number of restaurant-purchased meals eaten in a restaurant = 70

Number of restaurant-purchased meals eaten in a car = 22

Number of restaurant-purchased meals eaten in a home = 60

Step-by-step explanation:

Let the number of people that will eat in a restaurant be R.

Let the number of people that will eat in a car be C.

Let the number of people that will eat in a home be H.

From the information given in the problem we have,

R+C+H = 152 ____equation (1)

C+H-R = 12 ____equation (2)

R = H+10 ____equation (3)

1) Plugging in R=H+10 from equation 3 into the equation 2, we get

C+H-R=12

=> C+H-(H+10)=12

=> C+H-H-10=12

2) Cancelling out +H and -H, we get

C-10=12

3) Add 10 to both sides

C-10+10=12+10

4) Cancelling out -10 and +10, we get

C=22

5) Plugin C=22 in equation 1, we have

R+C+H = 152

=> R+22+H=152

Subtract 22 from both sides,

R+22+H-22=152-22

Cancelling out +22 and -22 from the left side, we get

R+H=130 ____let it be equation (4)

6) Plugin C=22 in equation 2, we have

C+H-R = 12

22+H-R = 12

Subtracting 22 from both the sides, we get

22+H-R-22 = 12-22

Cancelling out +22 and -22 from the left side,

H-R = -10 ____let it be equation (5)

7) Adding equation 4 and equation 5, we get

(R+H)+(H-R) = 130 + (-10)

=> R+H+H-R = 130-10

8) Cancelling out R and -R from the left side, we get

2H = 120

9) Dividing both sides by 2, we get

$\frac{2H}{2} = \frac{120}{2}$

10) Cancelling out the 2's from the left side, we have

H=60

11) Plugging in C=22 and H=60 in the equation 1, we have

R+C+H = 152

=> R+22+60=152

=> R + 82 = 152

12) Subtracting 82 from both the sides, we get

R + 82 -82 = 152 -82

13) Cancelling out +82 and -82 from the left side, we get

R = 70

8 0

3 years ago

5 Find the slope of the line that contains points (1,-3) and (-4,5).

ch4aika [34]

Answer:

gradient = m

m= $\frac{rise}{run}$

m= $\frac{1-(-4)}{-3-5}$

m= $\frac{5}{-8}$

3 0

3 years ago

What are the possible values of x in x2 + 3x + 3 = 0?

stealth61 [152]

Hello,

$x^2+3x+3=0\\

\Delta=9-4*3=-3\\

x= \dfrac{-3-i*\sqrt{3}}{2} \ or\ x= \dfrac{-3+i*\sqrt{3}}{2} \\

$

3 0

3 years ago

Read 2 more answers

Plz help me on this quick

Studentka2010 [4]

Answer: The third one

Step-by-step explanation: We can eliminate the first one right off the bat sinc we see that -4 has two outputs. Next, the graph's equation has no slope (x=3) so the input is all the same. Thirdly, the table shows a relationship between x and y and the numbers don't have a pattern that shows more than one output or input for a number. The fourth option are simply coordinates, it doesn't particularly tell us that all the coordinates are related to each other.

7 0

2 years ago