Answer:
When the water level is 3 cm, the rate at which the water level is rising is 30.86 cm/s.
Step-by-step explanation:
We first have to relate the height H of the pyramid with the volume V.
The volume of the pyramid is V=Sh/3, being S: area of the base square, and h: height of the pyramid.
The base is changing as the pyramid is filled with water.
Then, the volume for every height is:
The side of the square will grow linearly with the height. They start at H=0 and L=0 at the bottom of the pyramid, and they end at H=10 and L=3.
So we have:
If we replace in the volume equation we have:
We know that the rate of variation of the volume in time is contant and equal to 25 cm3:
We can derive the volume equation to calculate the variation of h in time:
The rate of variation of the height in time is dh/dt=278h^(-2). The units are cm/s.
When the water level is 3 cm, the rate at which the water level is rising is:
Answer:
I think 5
Step-by-step explanation:
If RS = PQ, and RS = 5, than PQ = 5
Answer:
The correct selections are:
B) After the donation collection period, compare the average or total amount collected from each of the two treatment groups.
C) A placebo is not being used
F) Randomly select 500 donors to receive the literature and 500 donors to receive the phone call.
Step-by-step explanation:
What this question requires from you, is to identify the correct characteristics of the study described. Let us explain why each of the selections was made.
B) After the donation collection period, compare the average or total amount collected from each of the two treatment groups: The purpose of the study is to determine the difference in the effectiveness of two methods of fundraising. Therefore at the end of the study, the average total amount raised from each group will be compared to determine which was more effective.
C) A placebo is not being used: Placebos are sham treatments used in a control group without their knowledge. The placebos do not produce any effect similar to the results anticipated the actual treatment. Here, no group is given sham treatment, there is no "control" group given placebos hence placebos are not used.
F) Randomly select 500 donors to receive the literature and 500 donors to receive the phone call: To remove any form of bias in the study, the selection of the groups is done at random, and the number of participants in each group is the same, so as to maintain uniformity during the comparison.
Answer:
7
Step-by-step explanation:
We know that $4.55 is the same as 455¢, and $0.65 is the same as 65¢. So, Mike bought [tex]\frac{455}{65} = \boxed{7}$ snicker bars.
Line through (-4,0) and (0,-2)
Slope is change in y over change in x
m = (-2 - 0)/(0 - -4) = -2/4 = -1/2
Answer: -2/4 = -1/2, second choice