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
strojnjashka [21]
3 years ago
9

In the aftermath of a car accident, it is concluded that one driver slowed to a halt in 20 seconds while skidding 1775 feet. If

the speed limit was 60 miles per hour, can it be proved that the driver had been speeding? (Hint: 60 miles per hour is equal to 88 feet per second.) We can guarantee that at some time from when the driver first pressed on the brake to when the car came to a complete stop the car was traveling
Mathematics
1 answer:
-Dominant- [34]3 years ago
7 0
Assume uniformly accelerated motion

Vf = Vo - at => a= [Vo - Vf] / t

Vf = 0, t = 20 s => a = Vo / 20

x = Vot - at^2 / 2

x = Vot - (Vo / 20) * t^2 /2

x = 1775 feet * [1 mile / 5280 feet] = 0.336 mile

t = 20 s

=> 0.336 = 20Vo - Vo(20)^2 /(40) = 20Vo - 10 Vo = 10 Vo

=> Vo = 0.336 /10 = 0.0336 mile /s

Vo = 0.0336 mile/s * 3600 s/h = 120.96 mile / h

Therefore, the car was way over the speed limit.



You might be interested in
Solve for x.<br> Your answer must be simplified.
Mnenie [13.5K]
I believe it is x < 120 (Btw the < is supposed to have a line under but I can’t put one! Pls give brainliest if can)
3 0
2 years ago
Delaney bought a new car for $34,742 she was surprised that the dealer then added 1,945.55. what was the sales tax rate for this
Gemiola [76]

Answer:

5.6%

Step-by-step explanation:

$34,742. X 5.6% = $1,945.55

6 0
3 years ago
normally distributed with mean 24.6 seconds and standard deviation 0.64 seconds;the lower finishing time, the better. If the qua
marshall27 [118]

Answer:

z=1.04

And if we solve for a we got

a=24.6 +1.04*0.64=25.27

So the value of height that separates the bottom 85% of data from the top 15% is 25.27.  

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

Solution to the problem

Let X the random variable that represent the finishing time of a population, and for this case we know the distribution for X is given by:

X \sim N(24.6,0.64)  

Where \mu=24.6 and \sigma=0.64

Solution to the problem

For this part we want to find a value a, such that we satisfy this condition:

P(X>a)=0.15   (a)

P(X   (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.  

As we can see on the figure attached the z value that satisfy the condition with 0.85 of the area on the left and 0.15 of the area on the right it's z=1.04. On this case P(Z<1.04)=0.85 and P(z>1.04)=0.15

If we use condition (b) from previous we have this:

P(X  

P(z

But we know which value of z satisfy the previous equation so then we can do this:

z=1.04

And if we solve for a we got

a=24.6 +1.04*0.64=25.27

So the value of height that separates the bottom 85% of data from the top 15% is 25.27.  

3 0
3 years ago
A cookie recipe requires 3/4 cup of flour to make 1.5 dozen cookies. How much flour is needed to make 1 dozen cookies
NISA [10]

Answer:

half a cup of flower -> 1/2

Step-by-step explanation:

i used a proportion to figure this out.

6 0
3 years ago
Find the absolute minimum and absolute maximum values of f on the given interval. f(t) = 3 (*sqaure root sign*) t (20 − t), [0,
mafiozo [28]

9514 1404 393

Answer:

  • maximum: 15∛5 ≈ 25.6496392002
  • minimum: 0

Step-by-step explanation:

The minimum will be found at the ends of the interval, where f(t) = 0.

The maximum is found in the middle of the interval, where f'(t) = 0.

  f(t)=\sqrt[3]{t}(20-t)\\\\f'(t)=\dfrac{20-t}{3\sqrt[3]{t^2}}-\sqrt[3]{t}=\sqrt[3]{t}\left(\dfrac{4(5-t)}{3t}\right)

This derivative is zero when the numerator is zero, at t=5. The function is a maximum at that point. The value there is ...

  f(5) = (∛5)(20-5) = 15∛5

The absolute maximum on the interval is 15∛5 at t=5.

5 0
3 years ago
Other questions:
  • Can someone help ?? please
    9·2 answers
  • 75,000 people went to watch the Huston Dynamos play Los Angeles Galaxy in the US Open final Cup At half time, Huston Dynamos wer
    11·1 answer
  • Given tanx=8/15 when pi &lt; x &lt; 3pi/2, find tan x/2.
    8·1 answer
  • The volume of a baseball is about
    7·1 answer
  • I need help with this question
    8·1 answer
  • Do 6 and 7 have any common factors
    9·2 answers
  • Simplify tanx×sinx+cosx​
    14·1 answer
  • Find the median of this data set <br> {7,2,5,8,14,8,10,2}<br><br> will give brainliest
    7·1 answer
  • X⁴-3x³+x-1 divided by x²+x-1​
    10·1 answer
  • The profit a company earns every month depends
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!