Contrast generators and electric motors.
2 answers:
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Answer:
1) 3.66 s
2) 124.44 m
3) 3.12 s
Explanation:
Let's start by first listing down the information in the question.
Red Car : 34 m/s
Blue Car: 28 m/s
Distance between them : 22 m
The difference in speed between the cars is: 34 - 28 = 6 m/s
This means that the red car is catching up to the blue car at a speed of 6 m/s.
1) We can solve this by just dividing the distance by the difference in speed. This becomes:
Thus it takes 3.66 seconds for the red car to catch up to the blue car.
2) We know from (1) that it took 3.66 seconds for the red car to catch up. Since the speed it was travelling at is constant, we only need to multiply it by the time from (1) to get the distance.
This becomes:
Thus the red car travels 124.44 m before catching up to the blue car.
3) If the red car starts to accelerate the moment we see it, the time taken to get to the blue car will be less than before. We can find this in a simple way.
We can use the motion equation :
Here s = 22 m
We can take u as the difference in speed. u = 6 m/s
Acceleration a = (2/3) m/s^2
Substituting the these into the equation we get:
Solving this for the variable 't' using the quadratic formula we get the following two answers:
t1 = 3.12 s
t2 = - 21.12 s
Since t2 is not possible, the answer is t1. This means it takes 3.12 seconds for the red car to catch up to the blue.
Answer:
Option d
The minimum angular separation between two objects that the Hubble Space Telescope can resolve is .
Explanation:
The resulting image in a telescope that will be gotten from an object is a diffraction pattern instead of a perfect point (point spread function (PSF)).
That diffraction pattern is gotten because the light encounters different obstacles on its path inside the telescope (interacts with the walls and edges of the instrument).
The diffraction pattern is composed by a central disk, called Airy disk, and diffraction rings.
The angular resolution is defined as the minimal separation at which two sources can be resolved one for another, or in other words, when the distance between the two diffraction pattern maxima is greater than the radius of the Airy disk.
The angular resolution can be determined in analytical way by means of the Rayleigh criterion.
(1)
Where is the wavelength and D is the diameter of the telescope.
Notice that it is necessary to express the wavelength in the same units than the diameter.
⇒
Finally, equation 1 can be used.
Hence, the minimum angular separation between two objects that the Hubble Space Telescope can resolve is .