Advertisements
Advertisements
प्रश्न
It is a well known fact that during a total solar eclipse the disk of the moon almost completely covers the disk of the Sun. From this fact and from the information you can gather from examples 2.3 and 2.4, determine the approximate diameter of the moon.
Advertisements
उत्तर १
The position of the Sun, Moon, and Earth during a lunar eclipse is shown in the given figure.
Distance of the Moon from the Earth = 3.84 × 108 m
Distance of the Sun from the Earth = 1.496 × 1011 m
Diameter of the Sun = 1.39 × 109 m
It can be observed that ΔTRS and ΔTPQ are similar. Hence, it can be written as:
`(PQ)/(RS) = (VT)/(UT)`
`(1.39xx10^9)/(RS) = (1.496xx 10^11)/(3.84xx10^(8))`
`RS = (1.39xx3.84)/1.496 xx 10^6 = 3.57 xx10 ^6 m`
Hence, the diameter of the Moon is 3.57× 106 m.
उत्तर २
From examples we get θ = 1920″ and S = 3.8452 x 108 m.
During the total solar eclipse, the disc of the moon completely covers the disc of the sun, so the angular diameter of both the sun and the moon must be equal. Angular diameter of the moon, θ= Angular diameter of the sun
= 1920″ = 1920 x 4.85 x 10-6 rad [1″ = 4.85 x 10-6 rad]
The earth-moon distance, S = 3.8452 x 108 m .’. The diameter of the moon, D = θ x S
= 1920 x 4.85 x 10-6 x 3.8452 x 108 m = 35806.5024 x 102 m
= 3581 x 103 m 3581 km.
संबंधित प्रश्न
How many significant figures are present in the 5005?
Round up the following upto three significant figures:
0.04597
Round up the following upto three significant figures:
2808
A student measures the thickness of a human hair by looking at it through a microscope of magnification 100. He makes 20 observations and finds that the average width of the hair in the field of view of the microscope is 3.5 mm. What is the estimate on the thickness of hair?
The mean diameter of a thin brass rod is to be measured by vernier callipers. Why is a set of 100 measurements of the diameter expected to yield a more reliable estimate than a set of 5 measurements only?
The mass of a box measured by a grocer’s balance is 2.300 kg. Two gold pieces of masses 20.15 g and 20.17 g are added to the box. What is
- What is the total mass of the box?
- What is the difference in the masses of the pieces to correct significant figures?
A SONAR (sound navigation and ranging) uses ultrasonic waves to detect and locate objects under water. In a submarine equipped with a SONAR the time delay between generation of a probe wave and the reception of its echo after reflection from an enemy submarine is found to be 77.0 s. What is the distance of the enemy submarine? (Speed of sound in water = 1450 m s–1).
A large ball 2 m in radius is made up of a rope of square cross-section with edge length 4 mm. Neglecting the air gaps in the ball, what is the total length of the rope to the nearest order of magnitude?
Solve the numerical example.
Nuclear radius R has a dependence on the mass number (A) as R =1.3 × 10-16 A1/3 m. For a nucleus of mass number A = 125, obtain the order of magnitude of R expressed in the meter.
Answer the following question.
Describe what is meant by order of magnitude.
How many significant figures should be present in the answer of the following calculations?
`(2.5 xx 1.25 xx 3.5)/2.01`
The mass and volume of a body are 4.237 g and 2.5 cm3, respectively. The density of the material of the body in correct significant figures is ______.
The numbers 2.745 and 2.735 on rounding off to 3 significant figures will give ______.
The length and breadth of a rectangular sheet are 16.2 cm and 10.1cm, respectively. The area of the sheet in appropriate significant figures and error is ______.
Significant figures in a measurement include which of the following?
Which of the following statements is correct about significant figures and accuracy?
A length L is measured as 125 m, which is also written as 12500 cm and 125000 mm. How many significant figures does this measurement have?
