Answer: Gravity is the force that keeps planets in orbit around the Sun. Gravity alone holds us to Earth's surface.
Planets have measurable properties, such as size, mass, density, and composition. A planet's size and mass determines its gravitational pull.
A planet's mass and size determines how strong its gravitational pull is.
Models can help us experiment with the motions of objects in space, which are determined by the gravitational pull between them.
Explanation:
Answer:
Their function is to produce sound by allowing the free edges of the folds to vibrate against one another and also to act as the laryngeal sphincter when they are closed.
Answers:
a) 
b) 
c) 
Explanation:
<h3>a) Impulse delivered to the ball</h3>
According to the Impulse-Momentum theorem we have the following:
(1)
Where:
is the impulse
is the change in momentum
is the final momentum of the ball with mass 
and final velocity (to the right) 
is the initial momentum of the ball with initial velocity (to the left) 
So:
(2)
(3)
(4)
(5)
<h3>b) Time </h3>
This time can be calculated by the following equations, taking into account the ball undergoes a maximum compression of approximately 
:
(6)
(7)
Where:
is the acceleration
is the length the ball was compressed
is the time
Finding from (7):
(8)
(9)
(10)
Substituting (10) in (6):
(11)
Finding :
(12)
<h3>c) Force applied to the ball by the bat </h3>
According to Newton's second law of motion, the force 
is proportional to the variation of momentum in time 
:
(13)
(14)
Finally:
It is important for physicians to be Respectful of patient use of alternative therapies
Alternative therapies usually have not gain a scientific approval from the scientific community, but there are some therapies that show positive results even though it is still has not proved by studies or researches. So it's important for physicians to be respectful if the patient choose to do it
