A Forwards B Backwards C Towards the ceiling D Wont move E Towards the seats 33

# A forwards b backwards c towards the ceiling d wont

This preview shows page 33 - 45 out of 47 pages.

A.) Forwards B.) Backwards C.) Towards the ceiling D.) Won’t move E.) Towards the seats 33 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Where will I move on the cart? A . ) Forwards B.) Backwards C.) Towards the ceiling D.) Won’t move E.) Towards the seats 34 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Types Friction Tension Normal Force Gravity Weight Magnetism 35 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Gravity Pull directed toward a second body. Free Fall - F g = m ( - g ) or F g = mg 36 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Gravity at rest Gravity acts on bodies in rest Free Fall - ~ F g = - F g ˆ j = - mg ˆ j 37 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Weight The weight W of a body is equal to the magnitude F g of the gravitation force on the body F net , y = ma y W - F g = m * 0 = 0 W = F g So, if gravity changes... 38 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Normal Force When a body presses against a surface, the sufarce deforms and pushes on the body with a normal force ~ F N perpendicular to the surface Free Fall ~ F N - F g = ma y ~ F N - mg = ma y ~ F N = m ( g + a y ) (1) 39 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Tension When a cord attached to a body is pulled tight with a force ~ T away from the body. Often assume the chord to be massless 40 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Friction Resistance of a force attempting to slide a body over a surface 41 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Newton’s third law (demo) Newton’s second law when two bodies interact, the forces on the bodies from eachother are always equal in magnitude and opposite in direction. 42 / 45 Course Overview Relative Motion Newton’s First Law Newton’s Second Law Types of Forces Newton’s Third Law Examples Newton’s third law (demo) Normal force ~ F N = ~ F g This holds even if the table was moving! 43 / 45 5.3.2. If an object is moving can you conclude there are forces acting on it? If an object is at rest, can you conclude there are no forces acting on it? Consider each of the following situations. In which one of the following cases, if any, are there no forces acting on the object?  #### You've reached the end of your free preview.

Want to read all 47 pages?

• Fall '08
• • • 