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
What kind of symmetry do you have
Keith_Richards [23]
During the daytime, I have mostly line symmetry.

During the night, I often have almost spherical symmetry.
5 0
3 years ago
Read 2 more answers
A skateboarder shoots off a ramp with a velocity of 7.1 m/s, directed at an angle of 61° above the horizontal. The end of the ra
dsp73

Answer:

Highest point reached  = 3.37 m

Explanation:

Initial velocity, = 7.1 m/s

Initial vertical velocity = 7.1 sin 61 = 6.21 m/s

Consider the vertical motion of skateboarder,

We have equation of motion, v² = u² + 2as

          Initial velocity, u = 6.21 m/s

          Acceleration, a = -9.81 m/s²

          Final velocity, v = 0 m/s

         Substituting

                       v² = u² + 2as

                       0² = 6.21² + 2 x -9.81 x s

                       s = 1.97 m

So from ramp the position it goes up by 1.97 m

       Highest point reached = 1.97 + 1.4 = 3.37 m    

6 0
2 years ago
A horizontal aquifer is overlain by 73.5 ft of water-saturated clay with a porosity of 0.4. The solid density of the clay partic
mr_godi [17]

Answer:

Explanation:

solution is in the attachment below

5 0
3 years ago
A container of soy milk has the instructions on its label to “shake well before opening ” The soy milk is most likely a ?
Elena-2011 [213]

Answer:

D. Suspension

4 0
3 years ago
5. You require a high-current battery to start a large tractor. While shopping
Yakvenalex [24]

Answer:

I have no clue sorry I wish I could help

3 0
2 years ago
Other questions:
  • A 55 newton force applied on an object moves the object 10 meters in the same direction as the force. What is the value of work
    7·1 answer
  • I need help to figure out how to solve this problem and solve it!!!
    7·2 answers
  • Help plz I don't understand ​
    5·1 answer
  • What is the current in each branch of the circuit?<br><br> 8: A<br> 10: A<br> 12: A
    12·2 answers
  • A bird watcher spots a sparrow in a tree. The sparrow sits in a nest that is 10.5 feet above the bird watcher's eye level, at a
    13·1 answer
  • 2. A car is moving with a constant speed of 10m/s. What is the total distance the car travels
    5·1 answer
  • What is a homogeneous mixture in which particles never separate?
    12·1 answer
  • Car A is traveling at 18.0 m/s and car B at 25.0 m/s. Car A is 300 m behind car B when the driver of car A accelerates his car w
    13·1 answer
  • Ayuda por favor cual es el objetivo del ultimate?
    10·1 answer
  • 7. Why are cooking pans made of aluminum? {Explain using the specific heat value of
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!