I need 10 really hard questions in gravitation chapter of class 9...
please do it fast and it should be really hard (out of the box thinking)
Answers
Explanation:
A body of mass 1kg is attracted by the earth which is equal to
2) what is gravitational force between 2 objects
3)the ball is thrown up the value of 'g' will be ?
4) the value of acceleration due to gravity
5) can we determine the gravitational mass of the body ?
6)who formulated the universal law of gravitation
7)Newton laws of gravity applies too ?
8)the mass on the moon is 40 kg what is the weight on earth .
ANSWERS
1)9.8N
2)attracted at all
3)remains constant
4)is least on equator
5)no
6)newton's law
7)all bodies respertive
8) 392N
Answer:
1. On the moon’s surface, the acceleration due to gravity is 1.67 ms-2. If the radius of the moon is 1.74 × 106 m, calculate the mass of the moon.
(G = 6.67 × 1011 Nm2kg-2)
2. From a cliff of 49 m high, a man drops a stone. One second later, he throws another stone. They both hit the ground at the same time. Find out the speed with which he threw the second stone.
3. How does the force of attraction between the two bodies depend upon their masses and distance between them? A student thought that two bricks tied together would fall faster than a single one under the action of gravity. Do you agree with his hypothesis or not? Comment.
4. Why does a body orbiting in space possess zero weight with respect to a spaceship?
5. Identical packets are dropped from two aeroplanes—one above the equator and other above the north pole, both at height h. Assuming all conditions to be identical, will those packets take same time to reach the surface of earth? Justify your answer.
6. Find the percentage change in the weight of a body when it is taken from the equator to the poles. The radius of the earth at the poles is 6357 km, the radius at the equator is 6378 km.
7. Suppose the mass of the earth somehow increases by 10% without any change in its size. What would happen to your weight? Suppose the radius of the earth becomes twice of its present radius without any change in its mass, what will happen to your weight?
8. Two bodies of masses 3 kg and 12 kg are placed at a distance 12 m. A third body of mass 0.5 kg is to be placed at such a point that the force acting on this body is zero. Find the position of that point.
9. How does the weight of an object vary with respect to mass and radius of the earth? In a hypothetical case, if the diameter of the earth becomes half of its present value and its mass becomes four times of its present value, then how would the weight of any object on the surface of the earth be affected?
10. Calculate the average density of the earth in terms of g, G and R.