CBSE CLASS 9- Q/A -GRAVITATION

Q1:What is cause of motion?

Answer: Force

Q2:Which physical quantity is required change the speed or the direction of motion of an object.?

Answer: Force

Q3: Due to which reason an object dropped from a height falls towards the earth.?

Answer: Graviataional force

Q4: Due to which reason planets go around the Sun?

Answer:The sun's gravity pulls the planet toward the sun.

Q5:Why moon goes around the earth.?

Answer: Gravitational force

Q6:What is the direction of force that keeps a body moving along the circular path?

Answer: Towards the centre

Q7:A stone is tied up with string & rotating circular path in horizontal plane . What happens when string snapped ?

Answer: straight line along tangent to the circular path

Q8:What the name of force suggested by Newton for attraction between objects in universe ?

Answer: gravitational force.

Q9: What is name of scientist who determined the value of G (GRAVIATAIONAL CONSTANT)?

Answer: Henry Cavendish

Q10: What is the term used for an objects falling towards the earth due graviational force only ?

Answer: Free

Q11: What is the nature of acceleration to gravity of an object under free fall?

Answer: Constant and independent from mass of object

Q12: Two objects A & B are under free fall and mass of A is greater than mass of B ? What is ratio of their acceleration?

Answer: one

Q13: Theearth attracts every object with a certain force and this force depends on the mass (m) of the object and the acceleration due to the gravity (g). Is it True ?

Answer:Yes,True

Q14: The mass of an object remains the same everywhere. Is it true or false ?

Answer: true

Q15: Weight and force have not unit of measurement. Is is true or Flase ?

Answer: False