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
IgorLugansk [536]
3 years ago
9

An air hockey game has a puck of mass 30 grams and a diameter of 100 mm. The air film under the puck is 0.1 mm thick. Calculate

the time required after impact for a puck to lose 10% of its initial speed. Assume air is at 15o C and has a dynamic viscosity of 1.75´10-5 N×s/m2 .
Physics
1 answer:
OverLord2011 [107]3 years ago
3 0

Answer:

time required after impact for a puck is 2.18 seconds

Explanation:

given data

mass = 30 g = 0.03 kg

diameter = 100 mm = 0.1 m

thick = 0.1 mm = 1 ×10^{-4} m

dynamic viscosity = 1.75 ×10^{-5} Ns/m²

air temperature = 15°C

to find out

time required after impact for a puck to lose 10%

solution

we know velocity varies here 0 to v

we consider here initial velocity = v

so final velocity = 0.9v

so change in velocity is du = v

and clearance dy = h

and shear stress acting on surface is here express as

= µ \frac{du}{dy}

so

= µ  \frac{v}{h}   ............1

put here value

= 1.75×10^{-5} × \frac{v}{10^{-4}}

= 0.175 v

and

area between air and puck is given by

Area = \frac{\pi }{4} d^{2}

area  =  \frac{\pi }{4} 0.1^{2}

area = 7.85 × \frac{v}{10^{-3}} m²

so

force on puck is express as

Force = × area

force = 0.175 v × 7.85 × 10^{-3}

force = 1.374 × 10^{-3} v    

and now apply newton second law

force = mass × acceleration

- force = mass \frac{dv}{dt}

- 1.374 × 10^{-3} v = 0.03 \frac{0.9v - v }{t}

t =  \frac{0.1 v * 0.03}{1.37*10^{-3} v}

time = 2.18

so time required after impact for a puck is 2.18 seconds

You might be interested in
In which parking situations should you use your parking brake?
VMariaS [17]
Answer:
-You should use your parking brake when on a hill/mountain with a huge drop because your car can’t slide off the edge.
-When there is a flood where your car is sitting because the water can’t carry your car
5 0
3 years ago
Read 2 more answers
What are the limitations of using solar panels?​
umka21 [38]
Location & Sunlight Availability.
Solar Panels use a large amount of space.
The Sun isn't always present.
Solar Energy is Inefficient.
There is an overlooked Pollution & Environmental Impact.
Expensive Energy Storage.
High Initial Cost.
8 0
2 years ago
An object is moving in a circle. If the radius of the object is doubled, and the period remains constant, the magnitude of the v
Anton [14]

Answer:

Twice

Explanation:

From the formula for velocity in a circle

V= 2πr/T

Where V is velocity

r is raduis

T is period

We see that as r increases V increases so if r is doubled V becomes doubled

4 0
3 years ago
Which of the following means that an image is real?
DochEvi [55]
To declare an image is real you would call it “authentic”
8 0
3 years ago
Read 2 more answers
Early experiments with light were understood by explaining the behavior of light in terms of waves. Which experimental result re
STALIN [3.7K]
The answer to what experimental result required considering the particle nature of light is A. The ultraviolet catastrophe of blackbody radiation.
8 0
3 years ago
Other questions:
  • A force of 50 pounds is directed 30 from the horizontal, find the vector that represents this force.
    12·1 answer
  • How does melting And burning sugar follow the law of conservation of mass
    8·2 answers
  • What is the correct name for this formula: SiO2?
    14·2 answers
  • During an autopsy and subsequent toxicology reports, it is discovered that a man died from arsenic poisoning. When investigating
    10·1 answer
  • Use the information from the article to answer the question.
    9·2 answers
  • What must occur for a process to be a chemical reaction?
    6·1 answer
  • The insulating solid sphere in the previous Example 24.5 has the same total charge Q and radius a as the thin shell in the examp
    9·1 answer
  • Electricity is the _____________ of electrons, because electrons _____________ from atom to atom.
    7·2 answers
  • How can you decrease the numbers<br> of calories you consume
    13·2 answers
  • Plz help!! This is timed!!!!
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!