Chapter 5
force and vectors
5.1 Force acting on an object
5.2 Vector Quantities
5.3 adding and subtracting Vectors
5.4 Balanced Force: Zero Resultant Force
5.5 Review Questions
5.6 Problems based on PISA and TIMSS
Pushing pulling, lifting, and stretching are just some of the different types of movement that we can see and explore in this chapter. Objects cannot move by themselves, but they need force to push or pull before they start to move or stop moving. One of natural forces is gravity. Gravity pulls things down to the ground. People invent a number of machines to make things in different ways and at different speeds. All machines that move involve some forces. You cannot see force, but you may experience force and see effect of force.
Children are playing (pulling) tug of war
Pushing by a man force
Falling (pull) by earth’s gravity
Water falls (pull) down due to earth’s gravity.
An empty sand barge is dragged (pulled) by a power of a tug boat.