The planets move eastward against the background of fixed stars with the exception of Venus, Uranus and Pluto moving westward as seen in Earth's sky . This apparent retreating movement is called Retrograde motion. It is illusion created by Earth's movement going by outer planets in their respective orbits.
Answer:
<u>Question 2</u>
<u>Part (a)</u>
Chlorine: type of compound = chloride
Oxygen: type of compound = oxide
<u>Part (b)</u>
The iron reacts with water and oxygen to form rust.
A water molecule is made up of two hydrogen atoms joined to one oxygen atom: Di-hydrogen oxide.
<u>Question 3</u>
This circuit is in parallel.
The current in a parallel circuit splits into different branches then combines again before it goes back into the supply.
We are told that A₁ = 0.8 A
As the lamps have <u>equal resistance</u>, the current splits equally:
A₂ = 0.4 A
A₃ = 0.4 A
Then combines again:
A₄ = 0.8 A
Explanation:
Radio Telescope:
1. FAST (Five Hundred Meter Aperture Spherical Telescope), China is the largest single dish radio telescope in the world with a dish of diameter 500 meters. Although its construction is over but its not yet functional.
2. Arecibo Observatory, Puerto Rico is the largest single dish <em>operational</em> radio telescope having a single dish of diameter 305 meters..
X - ray Telescope: Chandra X ray observatory also known as Advanced X-ray Astrophysics Facility (AXAF) is the largest x-ray telescope with aperture of 1.2 meters. It can detect X-ray sources which are 100 times fainter in comparison to any previous telescope.
Gamma ray telescope: Fermi Gamma ray telescope is the largest gamma ray telescope.
Wavelength = speed / frequency
(345 m/s) / (20,000 Hz) = 0.017 m
Answer:
20.0 cm
Explanation:
Here is the complete question
The normal power for distant vision is 50.0 D. A young woman with normal distant vision has a 10.0% ability to accommodate (that is, increase) the power of her eyes. What is the closest object she can see clearly?
Solution
Now, the power of a lens, P = 1/f = 1/u + 1/v where f = focal length of lens, u = object distance from eye lens and v = image distance from eye lens.
Given that we require a 10 % increase in the power of the lens to accommodate the image she sees clearly, the new power P' = 50.0 D + 10/100 × 50 = 50.0 D + 5 D = 55.0 D.
Also, since the object is seen clearly, the distance from the eye lens to the retina equals the distance between the image and the eye lens. So, v = 2.00 cm = 0.02 m
Now, P' = 1/u + 1/v
1/u = P'- 1/v
1/u = 55.0 D - 1/0.02 m
1/u = 55.0 m⁻¹ - 1/0.02 m
1/u = 55.0 m⁻¹ - 50.0 m⁻¹
1/u = 5.0 m⁻¹
u = 1/5.0 m⁻¹
u = 0.2 m
u = 20 cm
So, at 55.0 dioptres, the closet object she can see is 20 cm from her eye.
