Heena Sharma, Shubhankat Vats and, Rashmi Gupta Solutions for Chapter: Gravitation, Exercise 6: CHAPTER EXERCISE

A test tube floats in water with a small coin at its bottom. The mass of this test tube is equal to mass of seven coins and external volume is $16{\mathrm{cm}}^3$. It just sinks when the third coin is added. Calculate the mass of each coin. (Density of water is $1{\mathrm{gcm}}^{-3}$)

A stone is thrown vertically upward with an initial velocity of$50 \mathrm{m}/\mathrm{s}$. Take, $\mathrm{g}$as $10\mathrm{m}/{\mathrm{s}}^2$. Find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone?

If a planet existed whose mass was twice that of the earth and whose radius is $3$times greater. How much will a $1 \mathrm{kg}$ mass weigh in the planet? (acceleration due to gravity$=9.8 \raisebox{1ex}{$\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{${\mathrm{s}}^2$}\right.$)

What is upthrust? What are the quantities that can vary upthrust? How does it account for the floating of a body? When a partially immersed body is pressed down a little, what will happen to the upthrust?

How does a boat float in water?

State two factors on which magnitude of buoyant force acting on a body, immersed in a fluid depends.

A block of wood can float while a similar sized block of concrete can be used as an anchor. Why?

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.