Question

(a) What is the push or pull on an object known as?
(b) Why do the shape and size of a balloon change when filled with air or water?
(c) Name the quantity whose unit is ‘newton’$(N)$.

Answer 1

Hint:In science, force can be described as a push or a pull. A force is not something which an object has in it or contains but it is exerted on one object by another object. It is the energy or the strength exerted or beared by an object. Force is an interaction which when unopposed changes the motion of an object. It can cause an object having mass to change its velocity.

Complete answer:
(a) Force is necessary to move a stationary object from one place to another. The phenomenon required to push or pull an object is called force. Force can be defined as a push or pull on an object resulting from interaction of two objects. Whenever there is an interaction between the two objects, there will be a force acting on each object. When the interaction stops, the two objects will not experience force anymore.

(b) Whenever a balloon is filled with air or water, the shape and size of the balloon change because they occupy space which causes a change in shape.
(c) Force has the unit ‘newton’$(N)$.

Note:When a balloon filled with air is placed underwater, the water exerts a force on all sides of the balloon because water has higher pressure than air. The deeper the balloon is taken into water, the more the pressure and the smaller the size of the balloon.