1.can you identify the pictures in which people or objects can easily move? what are they? are they smooth or rough surfaces?

2. what about the pictures which seem to be harder for people and objects to move forth and back? what kind of surface is it, smooth or rough?

3.do people and objects move at the same force and speed on both smooth and rough surfaces? why do you think so?

4. what do you think affects the movement of different objects on any kind of surface they or move?

5. make a conclusion based on the given activity. ​