Topic Gravitation

Full Marks 30

- What is gravitation ? 1
- Write and mathematically explain the universal law of gravitation? 2
- Write the keplers law of planetary motion? 2
- What is free fall? 1
- Calculate the force of gravitation due to the earth on a ball of 1kg mass lying on the ground. 3

(Mass of the earth =6*10^{24}kg. radius of the earth = 6.4*10^{3}km. ,G=6.7*10^{11}Nm^{2}/kg^{2})

Free Test on Motion For Class 9th Physics

- Write the Archimedes principle ? 1
- Write the difference between Mass and Weight . 3
- What is Relative Density? 1
- Why is it difficult to hold a school bag having a thin and strong strip? 1
- A stone is allowed to fall from the top of tower 100 m high and at rhe same time another stone is projected vertically upwards from the ground with a velocity of 25m/s . calculate when and where the two stones will meet. 3
- The weight of Shivanee is 500 N on the Earth. Calculate her mass on the moon? 2
- How does a boat float in water? 1
- What is buoyancy? 1

Kepler’s Laws of Planetary Motion ,Free Fall and Acceleration Due to Gravity

- What is the acceleration due to gravity at a height equal to R/2 from the earth surface? 1
- The relative density of silver is 10.8 . Calculate the density of silver? 2
- Gravitational force acts on all objects in proportion to their masses . Why then a heavy object does not fall faster than a lighter object? 2
- A ball is thrown up vertically returns to the thrower after 6 sec. 3
- What is the velocity with which it was thrown up?
- The maximum height it reached?
- Its position after 4 second?