The Pull of the Earth – Maharashtra Board Class 9 Solutions for Science and Technology (English Medium)
AlgebraGeometryScience and TechnologyHindi
Solution 1:
- The ratio g (earth) /g (moon) is equal to 6:1.
- The value of the acceleration due to gravity increases as we move from the equator to the pole.
- If the earth shrinks to half of its radius, its mass remaining the same, the weight of an object on the earth will become four times
Solution 2:
Solution 3:
Solution 4:
The following factors affect the value of g:
-
- Shape of the Earth: The Earth is not perfectly spherical in shape. It is slightly flattened at the poles and bulges towards the equator. The value of g is maximum (9.83 m/s2) at the poles as the polar radius is minimum, while it is minimum (9.78 m/s2) at the equator as the equatorial radius is maximum.
- Depth: In the interior of the Earth, on an average, the value of g is less than that at the Earth’s surface. As the depth below the Earth’s surface increases, the value of g decreases, and finally, it becomes zero at the centre of the Earth.
Solution 5.1:
Mass | Weight | |
1 | The mass of a body is the quantity of matter contained in it. | The weight of a body is the gravitational force with which the Earth attracts it towards its centre. |
2 | It has magnitude but not direction. | It has both magnitude and direction. |
3 | It does not change from place to place. | It changes from place to place. |
4 | It can never be zero. | It is zero at the centre of the Earth. |
5 | The SI unit of mass is kilogram. | The SI unit of weight is newton. |
Solution 5.2:
Universal gravitational constant | Gravitational acceleration of Earth | |
1 | Universal gravitational constant numerically equals to the force of attraction between two unit masses separated by a unit distance. | Gravitational acceleration of the Earth is the acceleration produced in a body due to the gravitational force of the Earth. |
2 | Its value remains constant throughout the Universe. | Its value changes from place to place. |
3 | It has magnitude but not direction. | It has both magnitude and direction. |
4 | Its SI unit is Nm2/kg2. | Its SI unit is m/s2. |
Solution 6:
- The weight of a body is given by W = mg, where m is the mass of the body and g is the acceleration due to gravity. The value of g at the equator is less than that at poles. So, the value of g varies from place to place and m is the same everywhere.
- Hence, the weight of silver bought at the North Pole would be less when weighed at the equator. Therefore, Rahul’s friend will disagree about the weight of the silver.
Solution 7.1:
Data: W = 100N, g = 1.63 m/s2, m = ?
W = mg
The mass of the body is 61.35 kg.
Solution 7.2:
Data: g = 9.8 m/s2,
Mp = 2Me, Rp =2Re, gp = ?
Acceleration due to gravity,