120 likes | 199 Views
Which laws govern our universe?. Motion in 1 and 2 dimensions. Physics Year 12 2012. By PresenterMedia.com. Newtonian Mechanics. Newton’s First Law. Newton’s Third Law. Newton’s Second L aw. The Law of Gravity. Conservation of Energy. Conservation of Momentum.
E N D
Which laws govern our universe? Motion in 1 and 2 dimensions Physics Year 12 2012 By PresenterMedia.com
Newtonian Mechanics Newton’s First Law Newton’s Third Law Newton’s Second Law The Law of Gravity Conservation of Energy Conservation of Momentum
The Force be With You – huh? 1600kg 400Kg 5400N
Sample 1.4 continued The resultant force forward creates the acceleration of the car and trailer If there is a trailer attached, the trailer and car accelerate individually at the same rate as the whole system The resultant force on the trailer is composed of the force forward from the car and the friction opposing its motion The force on the car from the tow rope is the same as the force on the trailer exerted by the rope
GRAPHS and FORMULAS • We describe motion using graphs • We use formulae to help make calculations easier • We write what we know on a diagram • We write down what we want to know • We choose the easiest formula • We calculate the answer • We check that our answer makes sense • We check the units v = u + at x = ut + ½ at2 v2 = u2 + 2ax KE = ½ m v2 PE = mgh Draw Label Calculate
Conservation of Energy and Momentum Momentum is conserved in all collisions BUT IN Elastic Collisions IN Inelastic collisions • Kinetic Energy is conserved and is not considered to be “lost” as sound, heat, or light • Kinetic Energy is not conserved but is transformed into heat, sound and /or light
Circular Motion v Is there any acceleration? v v v
Circular Motion Velocity vector rotates by 2 • So acceleration, a = 2/T • But V = 2where R is the radius of the circle • So a = ? Or ???
Circular Motion Billy Tea http://www.youtube.com/watch?v=Hml7RVFULCA&feature=youtube_gdata_player Minidrome http://www.youtube.com/watch?v=kghtRevkUJA&feature=youtube_gdata_player NASCARS http://www.youtube.com/watch?v=yZa_S93bQWY&feature=youtube_gdata_player Loop the Loop in a real car http://www.youtube.com/watch?v=wiZoVAZGgsw&feature=youtube_gdata_player Bike and Cars circular track http://www.youtube.com/watch?v=hZOekFFSoWI&feature=youtube_gdata_player vectors http://www.youtube.com/watch?v=J0a6yoQ6ZRY&feature=youtube_gdata_player Science theatre http://www.youtube.com/watch?v=L6-kn2tB-9E&feature=youtube_gdata_player
Projectile Motion http://www.youtube.com/watch?v=rMVBc8cE5GU&feature=related http://galileo.phys.virginia.edu/classes/109N/more_stuff/Applets/ProjectileMotion/enapplet.html