Help me please with this homework

The placebo effect can weaken the _____ of an experiment.

erik [133]

The answer to this question would be: internal validity
Placebo effect happens when someone feels that they are getting better just because they got a drug, not by the substance inside the drug. That means even if the drug is empty the person can feel that it works.
Placebo effect can decrease the actual effect of the drug, thus decreasing the internal validity.

7 0

3 years ago

A 325 g object attached to a horizontal spring moves in simple harmonic motion with a period of 0.220 s. The total mechanical en

My name is Ann [436]

Answer:

Explanation:

Total mechanical energy = 1/2 m ω²A² where ω is angular frequency and A is amplitude .

Given

1/2 m ω²A² = 5.46

ω²A² = 2 x 5.6 / m

= 2 x 5.6 / .325

= 34.46

ωA = 5.87

maximum speed = ωA = 5.87 m /s

B )

angular frequency = 2π / T , T is period of oscillation .

= 2 x 3.14 / .22

= 28.54 s⁻¹

ω = $\sqrt{\frac{k}{m} }$

k is force constant and m is mass

$28.54=\sqrt{\frac{k}{.325} }$

k = 264.72 N/m

C)

ωA = 5.87

28.54 X A = 5.87

A = .2056 m

= 20.56 cm .

6 0

3 years ago

Of the following, which information is needed to determine the horizontal distance a projectile travels? Check all that apply. A

bagirrra123 [75]

I think there are about two correct statements. These are options A and B. The information needed to determine the horizontal distance a projectile travels would be the projectile's vertical acceleration and the angle of the projectile's initial velocity. Hope this answers the question. Have a nice day.

5 0

3 years ago

Which chemical change describes the reactions of elements and compounds that, in general, do not involve carbon and typically ta

KonstantinChe [14]

Answer:

Inorganic.

Explanation:

The chemical change which describes the reactions of elements and compounds that, in general, do not involve carbon and typically take place in laboratories or industries is inorganic.

In Chemistry, an inorganic chemical reaction can be defined as a type of chemical reaction that occurs without a carbon-hydrogen bond.

On the other hand, organic chemistry deals with reaction that occur in the presence of carbon-hydrogen bonds such as hydrocarbons.

3 0

3 years ago

Energy can transform between different types. For each of the following examples, identify two energy transformations and the ty

Artyom0805 [142]

For these examples, we are talking about mechanical energy, which is divided in two forms:

1. Kinetic Energy: Related to the motion of a body or object.

2. Potential Energy: It has two forms (a) Potential Gravitational Energy, which is the energy stored by a body or object, related to its position above the ground, and (b) Elastic Potential Energy, which is the energy stored by a body or object that is able to strech and compress (for example a spring coil, springboard, the net of a trampoline...)

Now that is clear the type of energy we are talking about, let's begin with the examples:

1) As we can see in the first figure attached, when the cannonball is fired has Kinetic Energy, and when it is in the air at a position in which the ball is in its maximum height ready to go back down, this is transformed to Gravitational Potential Energy.

2) In the second example (refer to 2nd figure attached), when the diver is in his position on the springboard waiting to jump, we are talking about Elastic Potential Energy. When he jumps this energy transforms to Kinetic energy.

3) For the final example (3rd figure attached), when the squirrel is standing on the tree has Gravitational Potential Energy. Then, when the squirrel jumps and is falling through the air, this is transformed in movement (Kinetic Energy). Finally, when it lands on the net of a trampoline, this is transformed to Elastic Potential Energy.

4 0

3 years ago

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