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3 years ago

Read the following scenario.

Physics

2 answers:

andrew-mc [135]3 years ago

5 0

Answer:

Their experimental design lacks control group

Explanation:

Based on what I read, the scientists don't have a control group as one of the main groups thus they cannot, in scientific sense, say that the medicine is better or worse. You always need a control group receiving no intervention because then we can compare groups and assess the effectiveness of that intervention (in our case if we had control group vs people who received the medicine, we could see if the people who received the medicine had improved condition etc when compared to participants who did not receive anything)

olganol [36]3 years ago

5 0

Answer:

The answer is B: the lack of a control group

Explanation:

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In rural areas, water is often extracted from underground by pumps. Consider an underground water source whose free surface is 6

stealth61 [152]

Answer:

W = 9533.09 Watt

Explanation:

given,

diameter of pipe inlet, d₁ = 10 cm

r₁ = 5 cm

diameter of pipe outlet, d₂ = 15 cm

r₂= 7.5 cm

head upto water level is to rise = 60 + 5

= 65 m

flow rate = 0.015 m³/s

we know

A₁ v₁ = A₂ v₂ = Q

π r₁² v₁ = π r₂² v₂ = 0.015

$v_1= \dfrac{r_2^2}{r_1^2} v_2$

$v_1= \dfrac{7.5^2}{5^2} v_2$

$v_1= 2.25 v_2$

$v_2 = \dfrac{0.015}{\pi r_2^2}$

$v_2 = \dfrac{0.015}{\pi 0.075^2}$

v₂ = 0.848 m/s

v₁ = 1.908 m/s

Applying Bernoulli's equation

$P_p = \dfrac{1}{2}\rho (v_2^2-v_1^2)+ \rho g h$

$P_p= \dfrac{1}{2}\times 1000\times (0.848^2-1.908^2)+ 1000\times 9.8\times 65$

$P_p= 635539.32 Pa$

P_p is the pump pressure

Power of the pump

W = P_p x Q

W = 635539.32 x 0.015

W = 9533.09 Watt

6 0

3 years ago

A baseball with a mass of 0.8 kg is moving at asperd of 45.0 m/s . what is the baseballs kinetic energy

Valentin [98]

Answer:

0.5*0.8*45^2. =810J

Explanation:

KE=1/2 mv^2

5 0

3 years ago

Please Help!!! Max points!!!!!!

svp [43]

Answer:

some kind of change

motion

KE = 1/2 m v^2

velocity

drag/air resistance

size

shape

Explanation:

8 0

2 years ago

5. A store clerk moved a 4.4-kg box of soap without acceleration along a shelf by pushing it with a horizontal force of magnitud

lesantik [10]

The box moved 0.73 m

<u>Explanation:</u>

Given data,

Magnitude 8.1 N Work on the box 5.9 J Clerk move a 4.4 Kg

Distance= work done on the box / Horizontal force on the magnitude

= 5.9/8.1

=0.728

Distance =0.73 m

The box moved 0.73 m

5 0

3 years ago

The biological levels of organization range from a single organelle all the way up to the biosphere in a highly structured hiera

Lemur [1.5K]

Answer:

A) R makes up Q which makes up P which makes up S.

B) Cells that work together make up tissues, which comprise organs.

D) In the model, the animal cells make up tissues such as muscle or connective tissue.

E) Organs, such as the stomach and intestines, make up organ systems which interact with one another to maintain homeostasis.

Explanation: I just got it right

5 0

3 years ago