Answer:
(a) Time t = 16.46 sec
(b) Time t =13.466 sec
(c) Deceleration = 
Explanation:
(a) As the train starts from rest its initial velocity u = 0 m/sec
Acceleration 
Final speed v = 80 km/hr

From first equation of motion v =u+at
So 
(b) Now initial speed u = 22.22 m/sec
As finally train comes to rest so final speed v=0 m/sec
Deceleration 
So 
(c) We have given that initial velocity = 80 km/hr = 22.22 m/sec
Final velocity v = 0 m/sec
Time t = 8.30 sec
So acceleration is given by

As acceleration is negative so it is a deceleration
Answer:
For number 2, it will be 8.
<span>` You can consider T to be in units of seconds/step. Frequency is the inverse of period, so
1/T = frequency and has units of steps per second. There will be 60 times as many steps in a minute.</span>
Answer:
a) 



b) 
Explanation:
From the exercise we got the ball's equation of position:

a) To find the average velocity at the given time we need to use the following formula:

Being said that, we need to find the ball's position at t=2, t=2.5, t=2.1, t=2.01, t=2.001



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b) To find the instantaneous velocity we need to derivate the equation


If you clap your hands, the shock causes the air around your hands to begin vibrating. When air particles vibrate, they bump into other particles near them. Then these particles begin to vibrate and bump into even more air particles. When the air particles begin vibrating the air inside your ear, you hear a sound.