1. Unit 2 - Forces

2. In this unit, you will be able to: 1.Define and describe concepts related to force – i.e. types of forces 2.State and apply Newton’s three laws of motion 3.Analyze the mathematical relationship among net force, mass and acceleration 4.Define and describe concepts related to the force of friction and gravity 5.Analyze the gravitation force acting on an object on the Earth’s surface 6.Design and carry out experiments to identify how friction affects the motion of a sliding object Pg. 53 Reflect on Your Learning

4. The Four Fundamental Forces 1.Gravitational force (weakest) force of attraction between all objects in the universe 2.Electromagnetic force force caused by electric charge 3.Strong nuclear force holds protons and neutrons together in the nucleus 4.Weak nuclear force responsible for the fact that some nuclei are radioactive

6. Free Body Diagrams A vector diagram showing all the forces acting simultaneously on an object is called a free body diagram. Drawing F.B.D.’s: 1.Draw compass point and suitable scale 2.Sketch the object isolated from it’s surroundings 3.Locate the centre of the object 4.Draw all force vectors acting on the object (note: always from the centre) i.e. FBD for a car travelling at constant speed 1 cm = 1 N

7. Draw F.B.D.’s for the following situations: 1.A car accelerating 2.A car slowing down 3.A car travelling at constant speed up a hill FBD Simulator 2.1 Prac. #7,9 UC #1-4