Answer:
t_a = 7 s
t_w = 5 s
Step-by-step explanation:
Given:
- The average speed in air v_a = 16 m/s
- The average speed in water v_w = 3 m/s
- The total distance D = 127 m
- The total time T = 12 s
Find:
How long did the stone fall in air and how long did it fall in the water?
Solution:
- Lets time taken by stone to drop through air as t_a = t_a.
- The time taken in water would be t_w = (12 - t_a)
- The total distance covered can be calculated as:
D = v_a*t_a+ v_w*(12 - t_a)
127 = 16*t_a + 3*(12 - t_a)
Simplify and solve for t:
91 = 16*t_a - 3t_a
13*t_a = 91
t_a = 7 s
t_w = 5 s
9514 1404 393
Answer:
(5, 6) is (h, k)
Step-by-step explanation:
Vertex form is an instance of the transformation of parent function f(x) = x². It is vertically scaled by a factor of 'a', and translated so the vertex is point (h, k). That is, the transformed vertex is h units right and k units up from that of the parent function (0, 0).
Parent:
f(x) = x^2
Transformed:
f(x) = a(x -h)^2 +k
__
When you compare the form to your specific instance, you need to pay attention to what it is that you're comparing. As the attachment shows, ...
- a = 2
- -h = -5 ⇒ h = 5
- k = 6
Hence the vertex is (h, k) = (5, 6). The second attachment shows this on a graph.
Answer: Random sampling
Step-by-step explanation:
- A random sampling technique is a method of sampling in which each member for the sample is chosen randomly from the population.
- Systematic sampling : It is a kind of random sampling in which the members get selected after a fixed interval but a random starting point.
- Convenience sampling : It is a kind of random sampling in which the members get selected on the basis of researchers convenience.
- Stratified sampling : It is a kind of random sampling in which the entire population is divided into a finite number of strata , the researcher select members for sample from each strata.
- Cluster sampling : It is a kind of random sampling in which the entire population is divided into clusters. Then a random sample of cluster is drawn by researcher.
In the given situation , 784 adults are selected after their telephone numbers were randomly generated by a computer.
Therefore , the type of sampling used here is : random sampling
Answer:
A,C,D
Step-by-step explanation:
Snap
Jona_Fl16
Answer:
Rachel
Step-by-step explanation:
We need to measure how far (towards the left) are the students from the mean in<em> “standard deviations units”</em>.
That is to say, if t is the time the student ran the mile and s is the standard deviation of the class, we must find an x such that
mean - x*s = t
For Rachel we have
11 - x*3 = 8, so x = 1.
Rachel is <em>1 standard deviation far (to the left) from the mean</em> of her class
For Kenji we have
9 - x*2 = 8.5, so x = 0.25
Kenji is <em>0.25 standard deviations far (to the left) from the mean</em> of his class
For Nedda we have
7 - x*4 = 8, so x = 0.25
Nedda is also 0.25 standard deviations far (to the left) from the mean of his class.
As Rachel is the farthest from the mean of her class in term of standard deviations, Rachel is the fastest runner with respect to her class.
