Grade 9 : Physics

A body of mass 1kg is attracted by the earth with a force which is equal to

     

   

• 9.8 N

• 6.67x 10¹¹

• 1 N

• 9.8 m/s

What is the gravitational force between two objects?

      

• attractive at large distances only

• attractive at small distances only

• attractive at all distances

• attractive at large distances but repulsive at small distances

The value of ‘g’

     

• Increases as we go above the earth’s surface

• Decreases as we go to the centre of the earth

• Remains constant

• Is more at equator and less at poles

The mass of the body on moon is 40kg, what is the weight on the earth.

      

• 240kg

• 392N

• 240N

• 400kg

 Newton’s law of gravitation applies to

      

• Small bodies only

• Plants only

• All bodies irrespective of their size

• For solar system

The distance between two bodies becomes 6 times more than the usual distance. The the F becomes

     

• 36 times

• 6 times

• 12 times

• 1/36 times

Two objects of different masses falling freely near the surface of the moon would

• have same velocities at any instant

• have different acceleration

• experience forces of same magnitude

• undergo a change in their inertia

A boy is whirling a stone tied to a string in a horizontal circular path. If the string breaks, the stone

• will continue to move in the circular path

• will move along a straight line towards the centre of the circular path

• will move along a straight line tangential to the circular path

• will move along a straight line perpendicular to the circular path away from the boy

In the relation F = G M m /d², the quantity G

• depends on the value ofg at the place of observation

• is used only when the Earth is one of the two masses

• is greatest at the surface of the Earth

• is universal constant of nature

Law of gravitation gives the gravitational force between

• the Earth and a point mass only

• the Earth and Sun only

• any two bodies having some mass

• two charged bodies only