Page 13 - Simplied Force

SIMPLIFIED COURSE ON SEE SCIENCE : CHAPTER- FORCE

29) Stone of 1kg and 5kg masses are dropped from the same height at lunar surface, which one will
reach on the surface fast and why?

Ans: When two stone of 1kg and 5kg masses are dropped from the same height at lunar surface, both will
reach on the surface simultaneously. It is because at the lunar surface, there is no air resistance (i.e. no
atmosphere). If there is no air resistance, the acceleration produces in the freely falling bodies, whatever
their masses, are the same.

30) What is the effect of earth’s gravity?

Ans: All the bodies present inside the gravitational field of a planet fall towards the surface of the planet
due to the effect of gravity of that planet. Gravity produces an acceleration on the falling bodies.

Additional Questions

1 What is gravitational field?
The region around a massive body in which a force of attraction is felt by other bodies is called the
gravitational field.

2 What is the relationship between the gravitational force between two bodies with their masses?

The gravitational force between two bodies is directly proportional to the product of their masses.

3 Under what condition a falling parachute has no acceleration?

A falling parachute has no acceleration when the gravity of the earth and the upthrust of the air acting
on the parachute are equal in magnitude but opposite in direction.
4 What is null point?

The points in space where the gravitational forces acting on the body become equal and opposite and
the net pull amounts to nothing are called null points.

5 Under what conditions gravitational constant is numerically equal to the force of gravitation?

The gravitational constant is numerically equal to the force of gravitation when the bodies have unit
mass and the distance between the bodies is unit.

6 What is weight?
Weight can be defined as the force with which it is attracted towards the centre of the earth.

7 What is free fall?

If a body is falling freely under the action of gravity alone neglecting air resistance, the motion is called
free fall.

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