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AlladinOne [14]
3 years ago
14

A rock is projected directly upward from ground level with an initial velocity of 90 ft/sec. After how many seconds will it retu

rn to the ground?
Mathematics
1 answer:
Nastasia [14]3 years ago
4 0
For this case we have the following equation of motion:
 h (t) = -16t ^ 2 + 90t
 Equaling the equation to zero we have:
 -16t ^ 2 + 90t = 0
 We look for the roots of the polynomial:
 (t) (- 16t + 90) = 0
 t1 = 0 (initial position)
 t2 = 90/16 = 5.625 s (time it reaches the ground again)
 Answer:
 
it will return to the ground in:
 
t = 5.625 s
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How do I round 8164 to the 4 decimal point?
aalyn [17]

Yeah, I agree with letsgoplayd. Your answer doesn't make any sense because 8164 is not a decimal. But we can look at another example:

8164.45678

In this case, the number rounded to the 4th decimal point (ten thousandths) would be

8164.45680

Because the digit after the 7 is 8, we should round the "78" part to "80".

These two rules will help:

5 or more, raise the score (add 1 to the digit, and let the digit directly behind it become 0.)

4 or less, let it rest (keep the digit, and let the digit directly behind it turn to a 0.)

Hope this helps! :)

6 0
3 years ago
I need help! This pattern repeats every 4 terms. The pattern is square, hexagon, trapezoid, triangle. What is the shape in the 7
alina1380 [7]
<h3>Answer:  Trapezoid</h3>

==========================================================

Explanation:

There are two ways to do this problem.

Method 1 involves listing out the terms until we reach the seventh one.

  1. square
  2. hexagon
  3. trapezoid
  4. triangle
  5. square
  6. hexagon
  7. trapezoid
  8. triangle

We see that the trapezoid is term 7.

-------------

Method 2 is faster and the one I recommend.

Since the pattern repeats every 4 items, this means we divide by 4 and look at the remainder. Ignore the quotient entirely.

7/4 = 1 remainder 3

The remainder 3 means that the answer is found in term 3, which is the trapezoid.

6 0
1 year ago
The path of a football can be modelled by the equation, h=-10d2+120d , where h represents the height, in metres, of the football
Marta_Voda [28]

Answer:

12 m

Step-by-step explanation:

The path of a football has been modeled by the equation:

h= -10d^2+120d

where h represents the height and d represents the horizontal distance.

When the ball lands, it means that its height is back at 0 metres. This means that we have to find horizontal distance, d, when height, h, is 0.

=> 0= -10d^2+120d

=> 10d^2 - 120d = 0

d(10d - 120) = 0

∴ d = 0 m

and

10d - 120 = 0

=> d = 120 / 10 = 12 m

There are two solutions for d when h = 0 m.

The first solution (d = 0 m) is a case where the ball has not been thrown at all. This means the ball has not moved away from the football player and it is still on the ground.

The second solution is the answer to our problem (d = 12 m). The ball lands at a horizontal distance of 12 m

3 0
3 years ago
Please someone answer for this question
Maslowich
First one is 5/3
Second one is: 5
Third one is: 15
3 0
2 years ago
Read 2 more answers
Strategies for rational numbers
hjlf

Answer:

A rational number is a number that can be expressed as a fraction where both the numerator and the denominator in the fraction are integers.

Step-by-step explanation:

what are u trying to calculate?

4 0
2 years ago
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