Question Text
Question 1 :
A group of students is designing an experiment to verify earth's freefall acceleration rate. They plan to evacuate the air from a bell jar using a vacuum pump, and then use a remotely controlled apparatus within the vacuum to drop a spherical metal object from rest. The group does not have a means to directly measure the sphere's acceleration rate, so they instead plan to measure other quantities about the sphere and its motion, and then will calculate an experimental value  for acceleration.<br/>Which one of the following options of measurements would provide the group with enough information to determine the sphere's acceleration rate, without making any unnecessary additional measurement?
Question 2 :
The force of attraction between two masses each of 1kg kept at a separation 1m is:
Question 3 :
The mass of the moon is 1% of mass of the earth.The ratio of gravitational pull of earth on moon to that of moon on earth will be:
Question 4 :
A planet has twice the density of earth but the acceleration due to gravity on its surface is exactly the same as on the surface of earth. Its radius in terms of earth's radius $R$ will be<br>
Question 5 :
The earth revolves around the sun in one year. If distance between them becomes double, the new time period of revolution will be:
Question 6 :
The value of $g$ (acceleration due to gravity) at earth's surface is ${ 10 } { m }{ s }^{ -2 }$. It's value at the centre of the earth which is assumed to be a sphere of radius $R$ metre and uniform mass density is,
Question 7 :
Mars has about $\left(\dfrac {1}{10}\right)^{th}$ as much mass as the Earth and its diameter is only half that of the earth. The acceleration of failing body on Mars is nearly:
Question 8 :
If the electrical force between two identical masses with same charge is equivalent to the gravitational force between them, then the charge on each object can be related to the masses as: 
Question 10 :
The height above the surface of earth at which acceleration due to gravity is half the acceleration due to gravity at surface of earth is ($R = 6.4 \times 10^6 m$)