Question

Ray1998 a year ago
Task 1
First, conduct some research to help you with later portions of this portfolio
assessment.
• Find a local building, take a picture of it, and estimate its height.
• Use the Internet to find some initial velocities for different types of fireworks.
Use one of these values

Task 2
Respond to the following items.
1. While setting up a fireworks display, you have a tool at the top of the
building and need to drop it to a coworker below. How long will it take the
tool to fall to the ground?
2. State whether the parabola represented by 2 ht t t ( ) 16 250 =− +

Answer 1

i got task one help me with the next part

Answer 2

\[x= -\frac{1}{2} g t^2 +v_0t +x_0\]

Answer 3

position of an object

Answer 4

nd to the following items.
1. While setting up a fireworks display, you have a tool at the top of the
building and need to drop it to a coworker below.
a. How long will it take the tool to fall to the ground? (Hint: use the first
equation that you were given above, 2
0 ht t h ( ) 16 =− + . For the building’s
height, use the height of the building that you estimated in Task 1.)
b. Draw a graph that represents the path of this tool falling to the
ground. Be sure to label your axes with a title and a scale. Your graph
should show the height of the tool, h, after t seconds have passed.
Label this line “Tool”.
© 2015 Connections Education LLC. All rights reserved.
2. State whether the parabola represented by 2 ht t t ( ) 16 250 =− + opens up or
down. Explain why your answer makes sense in the context of this problem.
3. One of the fireworks is launched from the top of the building with an initial
upward velocity of 150 ft/sec.
a. What is the equation for this situation?
b. When will the firework land if it does not explode?
c. Make a table for this situation so that it shows the height from time
t = 0 until it hits the ground.
d. Calculate the axis of symmetry.
e. Calculate the coordinates of the vertex.
f. Explain why negative values for t and h t( ) do not make sense for this
problem.
g. On the same coordinate plane from #1, draw a graph that represents
the path of this firework. Make sure that your graph is labeled
appropriately. Label this graph “Firework #1”.
4. Choose an initial velocity for a firework based on your research from Task 1
a. Write an equation that represents the path of a firework that is
launched from the ground with the initial velocity that you chose.
b. Suppose this firework is set to explode 3 seconds after it is launched.
At what height will this firework be when it explodes?
c. On the same coordinate plane that you have been using, draw a graph
that represents the path of this firework. Mark your graph to indicate
the point at which the firework will explode. Label this graph “Firework
#2”.
5. You launch a third firework. Decide whether you want to launch it from the
ground or from the roof of the building. Also, choose a height at which this
firework will explode and an initial velocity for this firework.
a. How long after setting off the firework should the delay be set?
b. On the same coordinate plane that you have been using, draw a graph
that represents the path of this firework. Mark your graph to indicate
the point at which the firework will explode. Label this graph “Firework
#3”.
6. What can you conclude about how the height of the building and the initial
velocity of the item launched affect the maximum height and the time it
takes to get there?
explain me how to do this im really gonna cry and i still hsve a test :(

Answer 5

-16t^2+v0t+25o

Answer 6

@jabez177

Answer 7

oh, its in ft
the equation given is the position of the tool at time t

we want to find the time when the tool falls and hits the ground (x=0)
so you have \[0=-16t^2+25\]

solve for t

Answer 8

5/4.-5/4?

Answer 9

@sooobored

Answer 10

why 5/4 twice?

Answer 11

5/4 the answer

Answer 12

i mean t=5/4s makes sense

5/4.-5/4 makes no sense

Answer 13

and yes its the answer

Answer 14

and the parabola goes downward?

Answer 15

i mean, the equation is tracking position vs time
since the tool is falling, the path of the tool will naturally be going down, hence downward parabola

Answer 16

you can also get that by looking at the -16t^2

Answer 17

h(t)16t^2+250t

Answer 18

thats for my downward parabola question i cn figure the graphs out

Answer 19

are you sure it isnt -16?

since gravity goes downwards

Answer 20

im not sure im just trying to figure this out

Answer 21

3. One of the fireworks is launched from the top of the building with an initial upward velocity of 150 ft/sec.

this is the question right?

Answer 22

i was trying to work on 2 but we can wok on 3

Answer 23

@sooobored

Answer 24

oh, sorry number 2

if the number is positive in front of t^2, then it opens upwards
if the number is negative infront of t^2, then it opens downwards

Answer 25

so 5/4 for 1
downward for number 2

Answer 26

One of the fireworks is launched from the top of the building with an initial
upward velocity of 150 ft/sec.
a. What is the equation for this situation?
b. When will the firework land if it does not explode?
c. Make a table for this situation so that it shows the height from time
t = 0 until it hits the ground.
d. Calculate the axis of symmetry.
e. Calculate the coordinates of the vertex.
f. Explain why negative values for t and h t( ) do not make sense for this
problem.

Answer 27

@sooobored

Answer 28

downward only if its -16t^2

Answer 29

ok remember
\[x=-\frac{1}{2}g t^2 +v_0 t +x_0\]

we gotta use that

Answer 30

vo is initial velocity and xo is initial position

Answer 31

1/2*g is just 16

Answer 32

the initial position is on the roof, which is like 25ft off the ground,
so xo=25

initial velocity is given as 150ft/s
so vo=150

plug in all the numbers and what do you get?

Answer 33

we are using the -16t^2+250t for number 2

Answer 34

is number 1 right?

Answer 35

just 250, not 250t

250t means theres an initial velocity of 250 ft/s

250 just means we're starting at a height of 250 ft

Answer 36

-16t^2+150t+25 is equation

Answer 37

for 3 a ?

Answer 38

sorry, the roof is 250 ft high, not 25ft

Answer 39

so y= -16t^2+150t +250

Answer 40

for equation for number 3 cause im looking at a professional on algebra.com except they had with 50 ?

Answer 41

and the time landing would it be 3.3?

Answer 42

WELL I DONT KNOW HOW HIGH THE ROOF IS

Answer 43

the height of the roof depends on whatever number they gave you

you can change around this number to get different problems

Answer 44

and different answers

but the process in solving the problems is the same

Answer 45

doesn't say anyhinh about a roof

Answer 46

3. One of the fireworks is launched from the (((top of the building))) with an initial upward velocity of 150 ft/sec.

top of building, roof, same thing

Answer 47

yes so would the eqiation be 16t^2+150t+25

Answer 48

only if it says the roof is 25ft high

Answer 49

but it used 250 from your previous problem

Answer 50

my teacher made this not me but its 150 for this one and 250 or the other one

Answer 51

we come up with a height for the building

Answer 52

no no, 150 refers to initial speed, which is in ft/s
initial height from the previous problem is only 250 ft

one is speed, the other is distance

Answer 53

now im confused

Answer 54

its like comparing apples to oranges

you can only compare/swap speeds with speed, distances with distances

Answer 55

just use 250 instead of 25

Answer 56

ok

Answer 57

i made a mistake from above

Answer 58

wheres does the 25 ft come in

Answer 59

exactly, it was suppose to be 250 ft

Answer 60

but my building is 25 ft like this example
a firework is launched from the top of a 50ft building with an initial upward velocity of 150 ft/sec
and he got +50 im so lost

Answer 61

does it say 50 somewhere in your problem?

i suggest making a new question and this time, post a screenshot instead of trying to copy and paste everything

too much information is being left out when copypasting

Answer 62

no because my building is not 50 ft its 25