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
vaieri [72.5K]
3 years ago
9

Suppose a star the size of our Sun, but of mass 9.0 times as great, were rotating at a speed of 1.0 revolution every 17 days. If

it were to undergo gravitational collapse to a neutron star of radius 15 km, losing 3/4 of its mass in the process, what would its rotation speed be? Assume the star is a uniform sphere at all times
Physics
1 answer:
Tanya [424]3 years ago
4 0
Use the conservation of angular momentum; angular momentum at the beginning = angular momentum at the end 
Conservation of angular momentum: 
I1 w1 = I2 w2 
Where I is the moment of inertia. For a sphere, I=2/5 m R^2. Substituting into the equation above we get 
w2 = I1 w1 / I2 = w1 m1 R1^2 / (m2 R2^2) 
w2 = w1 4 * (R1/R2)^2
= 4*(1)*(7E5/7.5)^2
= 3.48E10 revs/(17days)
= 2.04705882 x 10^9 revs/sec
You might be interested in
A solution is prepared by dissolving 49.3 g of KBr in enough water to form 473 mL of solution. Calculate the mass % of KBr in th
Lyrx [107]

Answer:

9.31%

Explanation:

We are given that

Mass of KBr=49.3 g

Volume of solution=473 mL

Density of solution =1.12g/mL

We have to find the mass% of KBr.

Mass =volume\times density

Using the formula

Mass of solution=1.12\times 473=529.76 g

Mass % of KBr=\frac{mass\;of\;KBr}{Total\;mass\;of\;solution}\times 100

Mass % of KBr=\frac{49.3}{529.76}\times 100

Mass % of KBr=9.31%

Hence, the mass% of KBr=9.31%

5 0
3 years ago
Calculate 8 ∙ 10-4 divided by 2 ∙ 102.
artcher [175]
8 * 10 - 4 
= 80 - 4
= 76

2 * 102 = 204

76/204 = 19/51

Hope this helps!
4 0
3 years ago
Read 2 more answers
A student does 25 J of work on the handle of a pencil sharpener. If the pencil sharpener does 20 J of work on the pencil, what i
allsm [11]

Answer:

80%

Explanation:

Efficiency of machine = work output/work input  ×100 %

From question, work output = 20J

Work input = 25J.

Therefore efficiency = 20/25 × 100 %

Efficiency = 20×4 %

Efficiency = 80%

I hope this was helpful, please mark as brainliest

3 0
3 years ago
What is the value of the thickness of the boundary layer at leading edge of the plate?
Harman [31]

Along the flow direction, the boundary layer's thickness varies. For ReT values between 260 and 780, the boundary layer thickness—defined as the depth at which the normalized concentration has a value of 1/e—ranges between 800 and 250 m.

<h3>What is the Boundary layer?</h3>
  • A boundary layer is the thin layer of fluid that forms immediately around a bounded surface in physics and fluid mechanics as a result of the fluid flowing along the surface.
  • A no-slip boundary condition is created as a result of the fluid and wall interaction (zero velocity at the wall).
  • After that, the flow velocity above the surface steadily rises until it reaches the bulk flow velocity again.
  • The term "velocity boundary layer" refers to the thin layer of fluid whose velocity has not yet recovered to that of the main flow.
<h3>What purpose does a boundary layer serve?</h3>
  • Because it is on the fluid's boundary, engineers refer to this layer as the boundary layer.
  • Many aerodynamics issues, such as wing stall, skin friction drag on an object, and the heat transfer that takes place in high-speed flight, depend heavily on the specifics of the flow within the boundary layer.

Learn more about Boundary layer here:

brainly.com/question/12974964

#SPJ4

7 0
1 year ago
Local environmental change have no effect on the global climate true or false
Otrada [13]

Answer:

false

Explanation:

Even small environmental changes have large effects because small things become bigger

5 0
3 years ago
Other questions:
  • Why does carbon dioxide have a higher bond order than water?
    12·1 answer
  • you throw a rock out of a 7th story window. you time that it takes 3.7 seconds to hit the ground, and measure that it hit the gr
    11·1 answer
  • Whats number 4 ?????????
    8·1 answer
  • An engine extracts 452.8kJ of heat from the burning of fuel each cycle, but rejects 266.7 kJ of heat (exhaust, friction,etc) dur
    7·1 answer
  • A 1,500 kg truck is towed sideways out of a mud-hole with a force of 15,000 N. How much acceleration is required for the tow tru
    8·1 answer
  • A d'Arsonal meter with an internal resistance of 1 kohm requires 10 mA to produce full-scale deflection. Calculate thew value of
    12·1 answer
  • Please answer my question I am having some trouble, please I would love for some help please and thank you.
    13·1 answer
  • All of the alkali metals, Group 1, have one valence electron. which of these would represent the oxidation number of the alkali
    10·1 answer
  • A force of 20 N acted on a 5 kg object, moving it a distance of 4 m. How much work was done on the object?
    7·1 answer
  • Explain what happens to the path of light as it hits a piece of black paper, a glass mirror, and a glass
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!