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2014-11-26T06:21:00+05:30

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These are estimates of their average speeds over some duration of time. These are not the fastest speeds.

Domestic animals

You could observe their movement in real life. If you observe their speed in meters/sec at home or on road or in some outing, then  you can estimate the speed in kmph. You can also estimate their speeds based on the relative speeds like a dog runs faster than a cat.

    Cat -  45 kmph                    Dogs - 50 kmph 
    Rabbit - 50 kmph                 Rats -  24 kmph
    Lizards - 0.3 kmph           Cows - 12 kmph
      Bullocks - 12 kmph          Goats - 25 kmph

Wild animals 

Cheetah - 100 kmph or more
Lion - 50 kmph to 60 kmph - cannot run at high speed for a long duration
Tiger 60 kmph
Elephants - 30 kmph
deer - 50 kmph - can run fast for relatively long duration

Wild horse -  60 km                           Swan on water -  10 kmph
Wild duck swims - 10 km/hour            Rabbit - 20 km to 25 km
Crow - 40 kmph                                 Eagle - 100 kmph or more
Wild dogs - 60 kmph
Crocodile - 10 kmph on land,  20 kmph in water

Fish  - 50 to 100 kmph depending on the type of fish
Frog - 18 t o 20 kmph

Bodies moving in uniform speed

1. Earth rotates around itself with a uniform speed (almost)
       So all of us are moving with a uniform speed (tangential) in circles, with 
       respect to a stationary observer outside earth. We have not taken into 
       account the revolution of earth around Sun here.

              Our speed = radius of earth * angular velocity
                          = 6400 km * 2 π / 24 hours = 1675.5 kmph

2. Trains and air planes move with uniform speed in between halts. Near 
     stations or airports, they accelerate or decelerate.  An express train 
     covers usually around 60 km in 3/4 hour non-stop between two big stations.
                 average speed  =  60 / (3/4) = 80 kmph

5.  Speed of Birds flying in air = distance traveled / time = 15 meters /sec = 54 kmph

7. Hard disk inside the computer.  It rotates at uniform speed.
          speed = 4,000 rpm - 10,000 rpm

9. Light wave moves at uniform speed of c = 3 * 10^8 m/sec            

10. A fan (ceiling) rotates at a uniform speed, same with the blade in a 
      kitchen - mixie or mixer.
       Tip of Fan wing : radius = 0.80 meter,  
        smallest speed = 5 rotations per sec
        Angular speed = 5 * 2 p radians/sec = 10 p rad/sec
         Uniform Linear speed of the tip (far end of a wing)  
                      = 0.80 * 10 p m/sec = 25.13m/s = 90.5 kmph

11. Blood inside our body moves (circulates) at uniform speed
         Pulse rate = 72 /min    
               Average distance from heart to a hand/leg  = 2.5 m
         Speed of blood flow = around   2.5m * 72 / min
                         = 180 m / min = 180 * 60/1000 = 10.8 kmph

Bodies moving with non uniform speed :

1. In a  cricket match the cricket ball is bowled and it travels the pitch at 
     an average speed in air and after bouncing from ground = 

               The ball takes 0.7 to 1 sec to reach batsman - observation.
        speed = distance / time = 20 meters / 0.7 sec = 20/0.7 * 18/5 = 103 kmph for a pacer
                    and 20 m / 1 sec = 72 kmph for a spinner. 

2. moon moves around the Earth with almost uniform speed

4. An object thrown in to air, like stone, moves at non-uniform speed.

4. Earth moves in an elliptical orbit non-uniform speed - its orbital speed 
    changes depending on its distance from the Sun. During summer Earth is 
      at 147 million km and (perihelon) during winter, it is at 152 million km.
         
          Linear Speed at perihelon = 2 π R / T  =  105,000 kmph
          Linear Speed at apihelon = 2 π R / T  =  109,000 kmph

5. Lift used to go up or down in a building - it moves at non-uniform speed - 
     accelerates and decelerates also.  Lift reaches 4th floor (10meters) in 
      10 seconds with uniform acceleration starting from rest. 

          So acceleration of an elevator is = 20/100 = 0.2 m/s²
            Speed = 0.2 * time  m/sec 



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