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Amanda [17]
3 years ago
12

Why is it important to know the direction of the force applied to a moving object and the direction in which the object is movin

g when determining the work done on the object?
A. Only the component of the force perpendicular to the motion is used to calculate the work.

B. If the force acts in the same direction as the motion, then no work is done.

C. When there is an angle between the two directions, the cosine of the angle must be considered.

D. A force at a right angle to the motion requires the use of the sine of the angle.
Physics
1 answer:
ELEN [110]3 years ago
3 0
C is correct.  The work-force relation is given by W=F·d, where F is force vector, and d is the displacement vector.  The dot is the dot product, which is a measure of how parallel the two vectors are.  It can be restated as the product of two vector magnitudes times the cosine of the angle between them.  Therefore work is a scalar, not a vector, since the dot product returns a scalar.  
W=Fdcos(\theta)
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Force is defined with Newton's equation F = ma, where m is an object's mass and a is its acceleration. It's unit is kg·m/s², which scientists have called a <em>Newton</em>. (Example: They used <em>9 Newtons</em> of force)

Pressure is force applied over an area, defined by the equation P = F/A. We can derive its from Newtons to get a unit of N/m², a unit scientists call the <em>Pascal</em>. (Example: Applying <em>100 Pascals </em>of pressure)

Finally, charge is given by the equation Q = It, where I is the current flowing through an object and t is how long that current flows through. It has a unit of A·s (ampere-seconds), but scientist call this unit a Coulomb. (Example: 20 <em>Coulombs</em> of charge)

4 0
3 years ago
When monochromatic light passes through the interface between two unknown materials at an angle θ where 0∘&lt;θ&lt;90∘, no chang
kirill115 [55]

Answer:

the correct one is the first,   the refractive index of the two materials must be the same

Explanation:

When a beam of light passes through two materials, it must comply with the law of refraction

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where n₁ and n₂ are the refractive indices of each medium.

In this case, it indicates that the light does not change direction, so the input and output angle of the interface must be the same,

       θ₁ = θ₂ = θ

substituting

          n₁ = n₂

therefore the refractive index of the two materials must be the same

When reviewing the answers, the correct one is the first

5 0
3 years ago
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Andrei [34K]
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6 0
3 years ago
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trapecia [35]
Kinetic energy is a result of mass in motion at a certain velocity.
<span>1 Joule = 1 kg • (m/s)<span>2
</span></span>the force as a function of mass of the object.
4 0
3 years ago
Students in an introductory physics lab are producing a region of uniform electric field by applying a voltage to two 20-cm-diam
earnstyle [38]

Answer:

69000 V

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