Answer:
A) B = 5.4 10⁻⁵ T, B) the positive side of the bar is to the West
Explanation:
A) For this exercise we must use the expression of Faraday's law for a moving body
fem = 
fem = 
- d (B l y) / dt = - B lv
B = 
we calculate
B = - 7.9 10⁻⁴ /(0.73 20)
B = 5.4 10⁻⁵ T
B) to determine which side of the bar is positive, we must use the right hand rule
the thumb points in the direction of the rod movement to the south, the magnetic field points in the horizontal direction and the rod is in the east-west direction.
Therefore the force points in the direction perpendicular to the velocity and the magnetic field is in the east direction; therefore the positive side of the bar is to the West
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:
Pulling a person down so we stick to the surface
Answer: The English origin was the largest
Answer:Infrared light has a wavelength that is longer than that of standard red light, and although considered part of the red color spectrum, infrared wavelengths are still much shorter
