Presentation on theme: "Forces & Motion Applied Physics and Chemistry Force Lecture 1"— Presentation transcript:
1 Forces & Motion Applied Physics and Chemistry Force Lecture 1
2 Force Fkick Fgrav Force a push or pull that one body exerts on another What forces are being exerted on the football?FkickFgrav
3 Force Force is a vector Two categories of force We need to know magnitude AND directionTwo categories of forceContact forcesField forces
4 Measuring Forces Forces are measured in newtons (kg . m/s2). Forces can be measured using a spring scale.
5 ForceBalanced Forcesforces acting on an object that are opposite in direction and equal in sizeno change in velocityequilibrium
6 Force Fnet Ffriction Fpull N W Net ForceSum of all the forces on an objectIf forces are unbalanced (not opposite and equal) velocity changes (object accelerates)If forces are balanced, velocity does not changeFnetFfrictionFpullNW
8 ConcepTest 2You are a passenger in a car and not wearing your seat belt.Without increasing or decreasing its speed, the car makes a sharp left turn, and you find yourself colliding with the right-hand door.Which is the correct analysis of the situation? ...
9 ConcepTest 21. Before and after the collision, there is a rightward force pushing you into the door.2. Starting at the time of collision, the door exerts a leftward force on you.3. both of the above4. neither of the above2. Starting at the time of collision, the door exerts a leftward force on you.
10 Newton’s First Law Newton’s First Law of Motion An object at rest will remain at rest and an object in motion will continue moving at a constant velocity unless acted upon by a net force.
11 Newton’s First Law Newton’s First Law of Motion Inertia “Law of Inertia”Inertiatendency of an object to resist any change in its motionincreases as mass increases