Gravitation Tes...

A ball is dropped from a height $$h$$. As it bounces off the floor, its speed becomes $$80 \%$$ of what it was just before it hit the floor. The ball then rises to a height equal to

A person jumps from the fifth storey of a building with load on his head. The weight experienced by him before reaching the earth will be:

The value of G for two bodies in vacuum is $$6.67 \times 10^{-11} N-m^2/Kg^2$$. Its value in a dense medium of density $$10^{10} gm/cm^3$$ will be:

FIll in the blank. 

Two balls of masses in ratio $$1 : 2$$ are dropped from the same height. Find the ratio of the forces acting on them during motion.

A body of mass $$1.5 \ kg$$ is dropped from a height of $$12 \ m$$. What is the force acting on it during its fall? $$(g=9.8 \ ms^{-2})$$

A mass $$m_1$$ is placed at the center of a shell of radius $$R$$. Another mass $$m_2$$ is placed at a distance $$R$$ from the surface of the shell and is immersed in oil of dielectric constant $$10$$. Find the gravitational force on $$m_1$$. (Assume that the shell and oil are practically massless).

The mass of the earth is $$80$$  times that of the moon. Their diameters are $$12800\ Km$$  and  $$3200\ Km$$ respectively. The value of g on moon will be _______, if its value on earth is $$980\ cm/s^2$$.

Two point masses each equal to $$1$$ kg attract one another with force of $$10^{-10} N$$. The distance between the two point masses is $$\displaystyle (G=6.6 \times 10^{-11} MKS$$ units$$)$$

A sphere of iron and another of wood of the same radius are held under water. Let $$F_{A} $$ and $$F_{B}$$ are the uptrusts of iron and wood respectively.Compare the upthrust on the two spheres.