Because there's no such thing as "really" moving.
ALL motion is always relative to something.
Here's an example:
You're sitting in a comfy cushy seat, reading a book and listening
to your .mp3 player, and you're getting drowsy. It's so warm and
comfortable, your eyes are getting so heavy, finally the book slips
out of your hand, falls into your lap, and you are fast asleep.
-- Relative to you, the book is not moving at all.
-- Relative to the seat, you are not moving at all.
-- Relative to the wall and the window, the seat is not moving at all.
-- But your seat is in a passenger airliner. Relative to people on the
ground, you are moving past them at almost 500 miles per hour !
-- Relative to the center of the Earth, the people on the ground are moving
in a circle at more than 700 miles per hour.
-- Relative to the center of the Sun, the Earth and everything on it are moving
in a circle at about 66,700 miles per hour !
How fast are they REALLY moving ?
There's no such thing.
It all depends on what reference you're using.
All electromagnetic waves travel at
299,792,458 meters per second
in vacuum.
Surface tension could be defined as the property of the surface of a liquid that allows it to resist an external force. The cohesive forces among liquid molecules are responsible for the phenomenon.
In simpler terms, it is the force that causes the molecules on the surface of a liquid to be pushed together and form a layer. The surface tension, then, is a measure of the cohesive forces that hold the molecules together.
Getting the actual measurement would give us 72 dynes/cm at 25°C . However, the force decreases significantly depending on the temperature.
Answer:
-2.869 rad/s2
Explanation:
Data given:
speed, vi at 95.0 km/h = 95 X (1 hour /3600 seconds) X (1000m / 1km)
Note that, for every 1 hour, there will be 60sec X 60sec = 3600 seconds
And for every 1km, there will be 1000m.
So, speed of 95.0 km/h = 26.389 m/s
speed, vi = r
ω (radius X angular velocity)
angular velocity, ωi = v/r
ωi = 26.389 m/s ÷ half of 0.88 m diameter
= 59.975 rad/s
decelerating to speed, vf at 60.0 km/h = 60 X X (1 hour /3600 seconds) X (1000m / 1km)
= 16.667m/s
The angular velocity for this speed = 16.667m/s ÷ half of 0.88 m diameter
= 37.879rad/s
How far the car goes is equivalent to the angular acceleration which equals to (ωf^2 - ωi^2) ÷ 2θ
= (37.879rad/s)^2 - (59.975 rad/s)^2 ÷ 2 (60 rev X 2π rad/rev)
= -2.869 rad/s2
