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.
(BELOW YOU CAN FIND ATTACHED THE IMAGE OF THE SITUATION)
Answer:
Explanation:
For this we're going to use conservation of mechanical energy because there are nor dissipative forces as friction. So, the change on mechanical energy (E) should be zero, that means:
(1)
With 
the initial kinetic energy, 
the initial potential energy, 
the final kinetic energy and 
the final potential energy. Note that initialy the masses are at rest so 
, when they are released the block 2 moves downward because m2>m1 and finally when the mass 2 reaches its maximum displacement the blocks will be instantly at rest so 
. So, equation (1) becomes:
(2)
At initial moment all the potential energy is gravitational because the spring is not stretched so 
and at final moment we have potential gravitational energy and potential elastic energy so 
, using this on (2)
(3)
Additional if we define the cero of potential gravitational energy as sketched on the figure below (See image attached), 
and we have by (3) :
(4)
Now when the block 1 moves a distance d upward the block 2 moves downward a distance d too (to maintain a constant length of the rope) and the spring stretches a distance d, so (4) is:
dividing both sides by d
, with k the constant of the spring and g the gravitational acceleration.
Change of State and a Physical Change
Answer:
A. Increasing the voltage of the battery
Explanation:
The relationship between voltage, V, current, I and resistance, R, is given as follows;
V = I × R
∴ I = V/R
From the above relationship, the current flowing in the circuit is directly proportional to the voltage of the battery, and inversely proportional to the resistance, 'R', of the circuit
Therefore, increasing the voltage, 'V', of the battery, increases the total current, 'I', flowing in the circuit.
Answer:
Explanation:
Given that
d= 1.5 in ( 1 in = 0.0254 m)
d= 0.0381 m
P= 75 hp ( 1 hp = 745.7 W)
P= 55927.5 W
N= 1800 rpm
We know that power P is given as
T=Torque
N=Speed
T=296.85 N.m
The maximum shear stress is given as
We know that 1 MPa =0.145 ksi
