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3 years ago

Which of the following is not an example of doing work?

Physics

2 answers:

Tju [1.3M]3 years ago

5 0

Maybe holding a tray in the cafeteria line

Whitepunk [10]3 years ago

5 0

Answer:

A. Holding a tray in the cafeteria line!

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A ray of light in glass strikes a water-glass interface at an angle of incidence equal to one-half the critical angle for that i

fomenos

Answer:

Explanation:

There will not be any internal reflection . it will be only refraction

critical angle = θ

Sinθ = 1 / μg

μg = 1.43 / 1.33 =

Sinθ = 1.33 / 1.43

= .93

θ = 68.44

angle of incidence i = 68.44 / 2

= 34.22

Sin i / Sin r = μw = 1.33 / 1.43

= .93

sin 34.22 / sinθ₁ = .93 , θ₁ is angle of refraction.

sinθ₁ = sin 34.22 / .93

= .5623 / .93

= .6047

θ₁ = 37 degree Ans

5 0

2 years ago

where σ(t) and σ(0) represents the time-dependent and initial (i.e., time =0) stresses, respectively, and t and τ denote elapsed

lesya [120]

Answer:

$E_r(6)=4.35614\ MPa$

Explanation:

$\epsilon$ = Strain = 0.49

$\sigma _0$ = 3.1 MPa

At t = Time = 32 s $\sigma$ = 0.41 MPa

$\tau$ = Time-independent constant

Stress relation with time

$\sigma=\sigma _0exp\left(-\frac{t}{\tau}\right)$

at t = 32 s

$0.41=3.1exp\left(-\frac{32}{\tau}\right)\\\Rightarrow exp\left(-\frac{32}{\tau}\right)=\frac{0.41}{3}\\\Rightarrow -\frac{32}{\tau}=ln\frac{0.41}{3}\\\Rightarrow \tau=-\frac{32}{ln\frac{0.41}{3}}\\\Rightarrow \tau=16.0787\ s$

The time independent constant is 16.0787 s

$E_{r}(t)=\frac{\sigma(t)}{\epsilon_0}$

At t = 6

$\\\Rightarrow E_{r}(6)=\frac{\sigma(6)}{\epsilon_0}$

From the first equation

$\sigma(t)=\sigma _0exp\left(-\frac{t}{\tau}\right)\\\Rightarrow \sigma(6)=3.1exp\left(-\frac{6}{16.0787}\right)\\\Rightarrow \sigma(6)=2.13451$

$E_r(6)=\frac{2.13451}{0.49}\\\Rightarrow E_r(6)=4.35614\ MPa$

$E_r(6)=4.35614\ MPa$

6 0

2 years ago

All but one statement applies to electromagnetic radiation

lina2011 [118]

<span>D) Electromagnetic radiation travels in the form of longitudinal waves.</span>

3 0

2 years ago

Which type of mirror would you use to cook a hot dog and why?

alexandr1967 [171]

As long as it’s a good mirror then any one of them is fine bc at the end of the day i’m getting a hot dog

8 0

2 years ago

Question:

KengaRu [80]

Answers:

1A) Al203

1B) SF6

2) Fe203 - iron oxide

3 0

3 years ago