Answer:
a. xy
Explanation:
The Faraday's law of induction can be used to express the relationship between the electric field line integral and the magnetic flux rate change in a closed loop. In order to ensure that the relationship between the two variables is equivalent to zero, the integration should be conducted on the xy plane. The correct option is option a.
Answer:
In order to improve visibility
Explanation:
Infrared telescopes are made using infrared cameras that contain infrared detectors which are solid-state and are maintained at very cold (cryogenic) temperatures
Infrared radiation is absorbed by water vapor which is present in the Earth's atmosphere, leading to the limitation of the use of infra red telescopes at high altitudes such as mountains, high flying planes or satellites
Answer:
t = 1,144 s
Explanation:
The simple pendulum consists of an inextensible string with a mass at the tip, the angular velocity of this is
w = √( L / g)
The angular velocity is related to the frequency and period
w = 2π f
f = 1 / T
w = 2π / T
Let's replace
2π / T = √ (L / g)
T = 2π √ (g / L)
Let's calculate
T = 2π √ (9.81 / 18.5)
T = 4,576 s
The definition of period in the time it takes the ball to come and go to a given point (a revolution) in our case we go from the end to the middle point that is a quarter of the path
t = T / 4
t = 4,576 / 4
t = 1,144 s
In a string of length L, the wavelength of the n-th harmonic of the standing wave produced in the string is given by:
The length of the string in this problem is L=3.5 m, therefore the wavelength of the 1st harmonic of the standing wave is:
The wavelength of the 2nd harmonic is:
The wavelength of the 4th harmonic is:
It is not possible to find any integer n such that 
, therefore the correct options are A, B and D.
