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
Montano1993 [528]
3 years ago
12

A ball is thrown from a height of 38 meters with an initial downward velocity of 3 m/s

Mathematics
2 answers:
Anit [1.1K]3 years ago
7 0

Answer:

  2.47 seconds

Step-by-step explanation:

The height is zero when the ball hits the ground, so time can be found by solving the quadratic ...

  -5t^2 -3t +38 = 0

for t in any of the usual ways. A graphing calculator gives a solution quickly. The quadratic formula can give you the "exact" solution.

For that formula, we have a=-5, b-3, c=38, so the solution looks like ...

  t = (-b ±√(b^2-4ac))/(2a)

  t = (-(-3) ±√((-3)^2 -4(-5)(38)))/(2(-5))

  = (3 ±√769)/(-10)

We're only interested in the positive solution, so ...

  t = -0.3 +√7.69 ≈ 2.473085

The ball hits the ground about 2.47 seconds after it is thrown.

ANTONII [103]3 years ago
4 0
<h2>Hello!</h2>

The answer is:

The ball will hit the ground after t=2.47s

<h2>Why?</h2>

Since we are given a quadratic function, we can calculate the roots (zeroes) using the quadratic formula.  We must take into consideration that we are talking about time, it means that we should only consider positive values.

So,

\frac{-b+-\sqrt{b^{2} -4ac} }{2a}

We are given the function:

h=-5t^{2}-3t+38

Where,

a=-5\\b=-3\\c=38

Then, substituting it into the quadratic equation, we have:

\frac{-b+-\sqrt{b^{2} -4ac} }{2a}=\frac{-(-3)+-\sqrt{(-3)^{2} -4*-5*38} }{2*-5}\\\\\frac{-(-3)+-\sqrt{(-3)^{2} -4*-5*38} }{2*-5}=\frac{3+-\sqrt{9+760} }{-10}\\\\\frac{3+-\sqrt{9+760} }{-10}=\frac{3+-\sqrt{769} }{-10}=\frac{3+-27.731}{-10}\\\\t1=\frac{3+27.731}{-10}=-3.073s\\\\t2=\frac{3-27.731}{-10}=2.473s

Since negative time does not exists, the ball will hit the ground after:

t=2.473s=2.47s

Have a nice day!

You might be interested in
Dose anybody know this need the answer asp
natali 33 [55]

Answer:

plots: -12,0

Step-by-step explanation:

6 0
2 years ago
Read 2 more answers
Please help ill give brainliest for sure to the right answer
storchak [24]

Answer:

linear and increasing

8 0
2 years ago
Read 2 more answers
The length of the base of a triangle is twice its height. if the area of the triangle is 44 square​ kilometers, find the height
xeze [42]
Let
x
be the height of the triangle.

Formular for area of Triangle
= ½ × base × height






thus,
{ \frac{1}{2} }(2x)(x)=44\ kilometers^2

Simplifying
x^2=44\ kilometers^2 \\\\ x= \sqrt{ 44 } \\\\ x=6.63\ kilometers
3 0
3 years ago
5 of 10
horrorfan [7]

Answer:

T-6÷2+5

Step-by-step explanation:

3 0
3 years ago
Please help solve h(t) =-16t^2+40t+20<br>​
gtnhenbr [62]

Answer: el último

Step-by-step explanation:

5 0
2 years ago
Other questions:
  • Find the common ratio of the following geometric sequence. If necessary, use the slash bar ( / ) to enter a fraction. Reduce fra
    7·1 answer
  • Plzzzzzzzzzzzz help me ASAP!!!!!!
    13·1 answer
  • Two complementary angles have measures of 15° and (x+5)°. what is the value of x? *
    8·1 answer
  • A rectangular room has an area of 131 1/4 square feet. The length of the room is 12 1/2 feet. What is the width, in feet, of the
    10·2 answers
  • Write an equation for a line that passes through (-1,4) and is parallel to 2y + 10x=-36
    8·1 answer
  • Which of the following geometric solids has five faces and five vertices?
    12·1 answer
  • What multiplies to -120 and adds up to 19
    6·1 answer
  • Find the annual interest rate.
    10·1 answer
  • Plz help me with this :(
    8·2 answers
  • The parabola opens:<br> O left<br> O up<br> O down<br> O right
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!