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Angelina_Jolie [31]
3 years ago
12

List how many significant figures the numbers contain. A. 205 cm. B. .00004 cm. C. 20 cm. D. 20. Cm.

Physics
1 answer:
stiv31 [10]3 years ago
7 0
A. 205 cm
   This has 3 significant figures: 2,0 and 5.

B. 0.00004 cm
   This has 1 significant figure: 4

C. 20 cm
   This has 2 significant figures: 2 and 0.

D. 20. cm
    This has 2 significant figures: 2 and 0 
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If the frequency of the motion of a simple harmonic oscillator is doubled, by what factor does the maximum speed of the oscillat
Maksim231197 [3]

Answer:

If the frequency of the motion of a simple harmonic oscillator is doubled , then maximum speed of the oscillator changes by the factor 2

Explanation:

We know that in a simple harmonic oscillator the maximum speed is given by

    v_{max} = Aw

  Here A is amplitude which is constant , so from above equation we see that maximum speed is directly proportional to w\\ of the oscillation .

  Since  w = 2 \pi f

      v_{max}^{|}/v_{max} = 2f/f = 2

  Where v_{max}^{|} is the maximum speed when frequency is doubled .

6 0
3 years ago
Your backpack has a mass of 8 kg. You drop it from a height of 1.3m. How much work is done by gravity as the backpack falls?
olga_2 [115]

Answer:

The answer is C.

Explanation:

I guessed and it was right

6 0
2 years ago
Read 2 more answers
A heat engine running backward is called a refrigerator if its purpose is to extract heat from a cold reservoir. The same engine
Goryan [66]

Answer:

a) 2.85 kW

b) $ 432

c) $ 76.95

Explanation:

Average price of electricity = 1 $/40 MJ

Q = 20 kW

Heat energy production = 20.0 KJ/s

Coefficient of performance,  K = 7

also

K=(QH)/Win

Now,

Coefficient of Performance, K = (QH)/Win = (QH)/P(in) = 20/P(in) = 7

where

P(in) is the input power

Thus,

P(in) = 20/7 = 2.85 kW

b) Cost = Energy consumed × charges

Cost = ($1/40000kWh) × (16kW × 300 × 3600s)

cost = $ 432

c) cost = (1$/40000kWh) × (2.85 kW × 200 × 3600s) = $76.95

4 0
2 years ago
How many neutrons does element x have if it's atomic number is 27 and it's mass number is 74
Makovka662 [10]

Atomic number=Proton count

Atomic mass=Proton count+ neutron count

Neuton Count=Atomic mass-Proton count

Proton count=Atomic number=27

Mass number=74

Neuton count= 74-27=47

3 0
3 years ago
At takeoff, a commercial jet has a speed of 72 m/s. Its tires have a diameter of 0.89 m. Part (a) At how many rev/min are the ti
34kurt

Answer:

a) Revolutions per minute = 2.33

b) Centripetal acceleration = 11649.44 m/s²

Explanation:

a) Angular velocity is the ratio of linear velocity and radius.

Here linear velocity = 72 m/s

Radius, r  = 0.89 x 0. 5 = 0.445 m

Angular velocity

         \omega =\frac{72}{0.445}=161.8rad/s

Frequency

         f=\frac{2\pi}{\omega}=\frac{2\times \pi}{161.8}=0.0388rev/s=2.33rev/min

Revolutions per minute = 2.33

b) Centripetal acceleration

               a=\frac{v^2}{r}

  Here linear velocity = 72 m/s

  Radius, r  = 0.445 m

Substituting

   a=\frac{72^2}{0.445}=11649.44m/s^2

Centripetal acceleration = 11649.44m/s²

6 0
2 years ago
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