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
SCORPION-xisa [38]
3 years ago
13

Why do some scientists not use controlled experiments?

Physics
1 answer:
Leviafan [203]3 years ago
7 0
Observational studies are a prime example. Observational data is more reflective of the real environments that scientists make their inferences to than controlled experiments. The disadvantage of observational studies is that the variability is far greater. <span />
You might be interested in
The lowest note possible on the piano is ____ hz, and the highest note possible is 4200 hz.
uranmaximum [27]
From what I herd and seen 27 hz. Is the lowest note you can hit.
7 0
3 years ago
Read 2 more answers
The electric force between two charged objects of charge +Q0 that are separated by a distance R0 is F0. The charge of one of the
vovikov84 [41]

Answer:

F=3F_o(\frac{R_o}{R_{o2}})^2

Explanation:

This problem is approached using Coulomb's law of electrostatic attraction which states that the force F of attraction or repulsion between two point charges, Q_1 and Q_2 is directly proportional to the product of the charges and inversely proportional to the square of their distance of separation R.

F=\frac{kQ_1Q_2}{R^2}..................(1)

where k is the electrostatic constant.

We can make k the subject of formula  as follows;

k=\frac{FR^2}{Q_1Q_2}...........(2)

Since k is a constant, equation (2) implies that the ratio of the product of the of the force and the distance between two charges to the product of charges is a constant. Hence if we alter the charges or their distance of separation and take the same ratio as stated in equation(2) we will get the same result, which is k.

According to the problem, one of the two identical charges was altered from Q_o to 3Q_o and their distance of separation from R_o to R_{o2}, this also made the force between them to change from F_o to F_{o2}. Therefore as stated by equation (2), we can write the following;

\frac{F_oR_o^2}{Q_o*Q_o}=\frac{F_{o2}R_{o2}^2}{3Q_o*Q_o}.............(3)

Therefore;

\frac{F_oR_o^2}{Q_o^2}=\frac{F_{o2}R_{o2}^2}{3Q_o^2}.............(4)

From equation (4) we now make the new force F_{o2} the subject of formula as follows;

{F_oR_o^2}*{3Q_o^2}=F_{o2}R_{o2}^2*{Q_o^2}

Q_o then cancels out from both side of the equation, hence we obtain the following;

3{F_oR_o^2}=F_{o2}R_{o2}^2.............(4)

From equation (4) we can now write the following;

F_{o2}=\frac{3F_oR_o^2}{R_{o2}^2}

This could also be expressed as follows;

F_{o2}=3F_o(\frac{R_o}{R_{o2}})^2

3 0
4 years ago
A 15.0-m uniform ladder weighing 500 N rests against a frictionless wall. The ladder makes a 60.08 angle with the horizontal. (a
grigory [225]

Answer:

a)  fr = 266.92 N,   fy = 1300 N,  b)    μ = 0.36

Explanation:

a) This is a balancing act.

Let's write the rotational equilibrium relations, where the turning point is the bottom of the ladder and the counterclockwise rotations are positive

             -w x - W x₂ + R y = 0         (1)

usemso trigonometry to find distances

            cos 60.08 = x / 7.5

            x = 7.5 cos 60.08

            x = 3.74 m

fireman

           cos 60.08 = x₂ / 4

           x2 = 4 cos 60

           x2 = 2 m

wall support

           sin 60.08 = y / 15

           y = 15 are 60.08

           y = 13 m

we substitute in equation 1

           R y = w x + W x2

            R = (w x + W x2) / y

            R = (500 3.74 +800 2) / 13

            R = 266.92 N

now let's write the expressions for the translational equilibrium

X axis

           R -fr = 0

           R = fr

           fr = 266.92 N

Y Axis  

           Fy - w-W = 0

           fy = 500 + 800

           fy = 1300 N

b) ask the friction coefficient

the firefighter's distance is

          cos 60.08 = x₃ / 9.00

          x₃ = 9 cos 60

          x₃ = 5.28 m

from equation 1

          R = (w x + W x₃) / y

          R = 500 3.74 + 800 5.28) / 13

          R = 468.769 N

we saw that

          fr = R = 468.769

The expression for the friction force is

          fr = μ N

in this case the normal is the ratio to pesos

        N = Fy

       N = 1300 N

        μ N = fr

        μ = fr / N

        μ = 468,769 / 1300

         μ = 0.36

7 0
3 years ago
Công thức dùng tính tần số dao động của con lắc lò xò
tino4ka555 [31]

Answer:

f = 1 / [ 2*pi*R*C*Sqrt(2*N)

Explanation:

f = 1 / [ 2*pi*R*C*Sqrt(2*N) is the formula. Sorry I answered in English.

6 0
3 years ago
How does the kinetic energy of an object affect the speed of an object?
sammy [17]

Answer:  Kinetic energy is energy in motion. For example would be the energy used or the momentum used to make a car drive down a hill. The kinetic energy of an object is proportional to to the square of its speed.

Explanation:

8 0
3 years ago
Other questions:
  • HELP PLZ HELPPPPPPPPPPPPPPPPPPPPPPP I need help
    5·1 answer
  • A bicycle and its rider have a combined mass of 80 kg and a speed of 6 m/s. What is the magnitude of the average force needed to
    11·2 answers
  • All of the following are stages of change EXCEPT
    13·1 answer
  • Why are very high temperatures and pressures required for fusion to occur?
    15·1 answer
  • A ball is thrown upward. At a height of 10 meters above the ground, the ball has a potential energy of 50 joules (with the poten
    12·1 answer
  • If two waves with identical crests and troughs meet, what is happening? The wave is reflecting. Constructive interference is occ
    9·2 answers
  • . Which is the transfer of energy as waves moving through space?
    7·1 answer
  • The unit of force, Newton is a derived unit. (give reasons) ​
    8·1 answer
  • A screw Jack whose pitch is 2mm is used to raise a bus of mass 900kg through height of 20cm. The length of the Tommy of the Tomm
    6·1 answer
  • What should you do in the intermediate steps of a numerical calculation?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!