Exploring Forces
Chapter Name : Force And Pressure |
Sub Topic Code : 101_08_11_03_01 |
Topic Name : Exploring Forces |
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Sub Topic Name : Exploring Forces |
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Introduction
Directional characteristic of forces
Pre-Requisites:
What is a force?
Activity:
Observe: 1. When you play tug-of-war, the team that exerts greater force wins as the net force will be in their direction. 2. When two people put same effort to push an object from either side, it doesn't move when the magnitude of the forces are the same. 3. Its easier for 4 people to push a car because the force applied by each of them gets added up.
Real Life Question:
Its easier for 4 people to push a car than 1!
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Direction | It shows from which side the force is being applied. |
| Magnitude | This is the "number" or intensity of the force. This quantity does not indicate the direction in which the force is applied. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Applet | Demonstration for resolving a vector |
Real life uses :
Motion of bus cars, trains etc requires a force. Earth pulls everything down. To keep the aeroplane floating, it must have another force pushing it upwards
Places to visit :
Children's Science Museum. Many of them have an exhibit on forces.
Practical examples around us
| Examples | Explainations |
|---|---|
| A ball rolling on the flat surface will stop after travelling some distance. | The push that you give to the ball helps it go further. But the floor in contact with the ball exerts frictional force in opposite direction. As long as the push force is greater than friction, the ball keeps moving. When the push force equals friction force, the ball stops. |
| Elevators move up an down. | The magnitude of the force might be the same, but the direction of force is different. |
What you learn in Theory:
Forces a vector quantity have both magnitude and direction. Thus, the effect of force depends not only on the magnitude but also on the direction of application. Therefore, Net Force comes into picture.
What you learn in Practice:
The correct application of forces to achieve the required effect.