1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
riadik2000 [5.3K]
3 years ago
11

A model rocket is launched straight upward. The solid fuel propellant pushes the rocket off the ground at an initial velocity of

50 feet per second.
s(t)= -4t2 + 50t - 84. Show work to get credit


a. What is the maximum height reached by the rocket?

b. What time will it reach the maximum height?

c. You forgot to put the parachute in the rocket. When will the rocket hit the ground?
Mathematics
1 answer:
anastassius [24]3 years ago
3 0

Answer:

a) 72.25sec

b) 6.25secs

c) after 10.5secs and 2 secs

Step-by-step explanation:

Given the height reached by the rocket expressed as;

s(t)= -4t^2 + 50t - 84

At maximum height, the velocity of the rocket is zero i.e ds/dt  = 0

ds/dt = -8t + 50

0 = -8t + 50

8t = 50

t = 50/8

t = 6.25secs

Hence it will reach the maximum height after 6.25secs

To get the maximum height, you will substitute t - 6.25s into the given expression

s(t)= -4t^2 + 50t - 84

s(6.25) = -4(6.25)^2 + 50(6.25) - 84

s(6.25) = -156.25 + 312.5 - 84

s(6.25)  = 72.25feet

Hence the maximum height reached by the rocket is 72.25feet

The rocket will reach the ground when s(t) = 0

Substitute into the expression

s(t)= -4t^2 + 50t - 84

0 = -4t^2 + 50t - 84

4t^2 - 50t + 84 = 0

2t^2 - 25t + 42 = 0

2t^2 - 4t - 21t + 42 = 0

2t(t-2)-21(t-2) = 0

(2t - 21) (t - 2) = 0

2t - 21 = 0 and t - 2 = 0

2t = 21 and t = 2

t = 10.5 and 2

Hence the time the rocket will reach the ground are after 10.5secs and 2 secs

You might be interested in
Find the value of x.
Tatiana [17]

Answer: The answer is x = 6 units.

Step-by-step explanation: Please refer to the attached diagram

The diagram in the question shows two triangles placed on each other and for convenience sake has been labelled ABDCE. Triangle ABC is a right angled triangle, and so is triangle ADE. From the marks on the lines, we can infer that line AD is equal in measurement to line DB. Also line AE is equal in measurement to line EC.

Therefore we can see the similarity in both triangles, if AD and AE equals DB and EC, then it follows that DE equals BC.

Hence if AD = DB and

AE = EC, and

DE = BC

Then, x - 3 = ½x

(½x can also be expressed as x/2)

x - 3 = x/2

By cross multiplication we now have

2(x - 3) = x

2x - 6 = x

By collecting like terms we now have

2x - x = 6

x = 6

8 0
3 years ago
Which angle in def has the largest measure ?
Luden [163]
So you question is most likely about a triangle DEF with the 3 angles being named D, E, F. The triangle would look something like the image attached below.
If that is what is being asked then i need more info to answer but
By Definition it would be 180 degrees.

7 0
3 years ago
Dylan is evaluating the expression 13 + 19 + 7 + 10. At one step in his work, Dylan rewrites the equation as 13 + 7 + 19 + 10. W
AlekseyPX

Answer:

Communicative Property

Step-by-step explanation:

The communicative property is basically just switching numbers around but still leading to the same answer, if you could see, both of the equations lead to the same answer, 49. Here is a chart to help you out.

7 0
3 years ago
Please please 1,2,3 please help!!
zhannawk [14.2K]
Look online and find the answers to the workbook that's what I did and I never failed workbook things
6 0
3 years ago
Helpppppppppp me pleaseeeeeeeeeee
MrRa [10]
The answer is C .12/15 since you can divide A,B,D and get 2/3 but you cannot with C 
5 0
3 years ago
Read 2 more answers
Other questions:
  • Mr. Watkins earns $35 an hour at his new job. During a typical month, he works a total of 160 hours. Mrs. Watkins is a homemaker
    12·1 answer
  • FIND INVERSE OF Y=3X+9/7
    10·1 answer
  • Find the y-intercept of the line 2x+10y=20 type in an ordered pair as your answer.
    12·1 answer
  • If the edge length of a cube is 12 feet, what is the correct way to write the expression to represent the volume of the cube in
    7·2 answers
  • your rectangular yard is 10 feet wide and 26 feet long.How many square feet of grass do you need to plant if you want to cover t
    15·1 answer
  • Help with this question please
    15·1 answer
  • Identify the graph of the equation y = 2x2 − 2x + 1.
    13·2 answers
  • The coordinate grid shows the cost of different numbers of book marks. How many cents do 4 bookmarks cost?
    14·1 answer
  • 121 meals / 11 days find the unit rate​
    13·1 answer
  • f(x) = –25 + 5xA) Graph the function and find it’s intercepts. B) what does each intercept represent?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!