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
schepotkina [342]
3 years ago
6

The stopping distance of a car is modeled by the function d = 0.05r(r + 2) where d is the stopping distance of the car measured

in feet and r is the speed of the car in miles per hour. If skid marks left on the road are 75 feet long, how fast was the car traveling?
Mathematics
1 answer:
adell [148]3 years ago
3 0

Answer:

The car was moving approximately at a speed of 37.74 miles per hour.

Step-by-step explanation:

We are given the following in the question:

The stopping distance of a car is given by

d = 0.05r(r + 2)

where d is the stopping distance in feet and r is speed of the car in miles per hour.

The stopping distance is 75 feet, we have to find the speed of the car,

Putting d = 75 in the equation, we get,

75 = 0.05r(r + 2)\\r^2 + 2r = 1500\\r^2 + 2r-1500 = 0\\\\r =\dfrac{-2\pm \sqrt{4-(4)(1)(-1500)}}{2}\\\\r\approx -39.74,37.74

Thus, the car was moving approximately at a speed of 37.74 miles per hour.

You might be interested in
Which expressions are equivalent to (5⋅x)⋅3 ? Drag and drop the equivalent expressions into the box.
marysya [2.9K]
<h2>Greetings!</h2>

Answer:

3⋅(5⋅x)

5⋅(x⋅3)

15x

Step-by-step explanation:

As the values are inside the brackets, it does not matter what side the (x3) is on, so 3⋅(5⋅x) is equivalent.


Multiplying the contents of the brackets in the third one (x * 3) by 5 gives the same value as 3 * (x * 5) so 5⋅(x⋅3) is also equivalent.


On multiplying the brackets out:

5 * x = 5x

5x * 3 = 15x

So 15x is also equivalent.


<h2>Hope this helps!</h2>
3 0
3 years ago
Work out the area of this circle.<br> Give your answer in terms of it and state its units.<br> 6 mm
andrey2020 [161]

Answer:

113.142 mm

Step-by-step explanation:

Easy.

Formula:

pi x radius x radius

Solution: 3.141592654 or 22/7 for pi

22/7 x 6 x 6 = 113.142 mm

6 0
3 years ago
Read 2 more answers
Omg plzzzzzzzzzzz HELPPPPPPPPPPP MEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
natta225 [31]

Answer:

25

Step-by-step explanation:

5 0
2 years ago
Read 2 more answers
Please help with this question ​
svetlana [45]

Answer:The answer to this question would be "1470"To find the volume, all you need to do is Multiply the length, width, and height of the object together and you can find the Volume.Hope this helps, Please mark as Brainliest.

Step-by-step explanation:have a good day.

6 0
2 years ago
Read 2 more answers
Can someone help or show me how to simplify this equation 22.5+7(n-3.4)
Scorpion4ik [409]
<span>22.5+7 (n-3.4)=19.8n

We simplify the equation to the form, which is simple to understand
<span>22.5+7(n-3.4)=19.8n

Reorder the terms in parentheses
<span>22.5+(+7n-23.8)=19.8n

Remove unnecessary parentheses
<span>+22.5+7n-23.8=+19.8n

We move all terms containing n to the left and all other terms to the right.
<span>+7n-19.8n=-22.5+23.8

We simplify left and right side of the equation.
<span><span>-12.8n=+1.3

</span>We divide both sides of the equation by -12.8 to get n.
<span>n=-0.1015625</span></span></span></span></span></span></span>
5 0
3 years ago
Read 2 more answers
Other questions:
  • during a long race a professional cyclist was able to sustain a speed of 20 miles per hour. How far could this cyclist travel at
    15·1 answer
  • I'm a bit confused On this question so I'll take any help
    11·1 answer
  • There are 24 hours in a day and 7 days in a week. Write an expression to show how many hours there are in t weeks.
    15·1 answer
  • Help? 100pts giving brainliest (:<br> Find x and y, given that line KL and line MN are parallel
    8·2 answers
  • define f(1) in a way that extends f(s)=(s^3-1)/(s^2-1) to be continuous at s=1. Show step-by-step solution.
    7·1 answer
  • Can anyone help me solve this
    6·1 answer
  • A store buys frozen burritos from a supplier for $1.40 each. The store adds a markup of 80% to determine the retail price. This
    15·1 answer
  • Jason is training to run in a marathon. His goal for this week is to run a minimum of 330 miles. So far this week, he has alread
    9·1 answer
  • Sweet Swannies Store had a sale offering 15% off all its merchandise.
    6·1 answer
  • Jhumpa has $55 in her savings account. This is $21 more than
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!