1/17/14, Friday

Post date: Jan 17, 2014 3:17:20 PM

Learning Targets

(12) Draw a well-labeled, free-body diagram showing all real forces that act on the object.

(13) Write down the vector equation that results from applying Newton’s Second Law to the object, and take components of this equation along appropriate axes.

(14) Students should be able to analyze situations in which an object moves with specified acceleration under the influence of one or more forces so they can determine the magnitude and direction of the net force, or of one of the forces that makes up the net force, such as motion up or down with constant acceleration.

Activities

• • Hand in Assessment 4

  • Discuss answers to assessment 4

  • LT 12-13 practice

    • example problem 5.5

    • A 15 kg box repels from a helicopter. The box uses the ropes to keep its descent speed constant. Their is also a strong wind that pushes the box horizontally with a force of 25 N. Draw a free body diagram for the box, and write the X and Y component forms of Newton's 2nd law for the equation.

  • LT 12, 14 practice

    • example problem 5.7

    • A 15 kg box repels from a helicopter. The box uses the ropes to keep from getting crumpled upon landing, and brakes with a force of 120 N. A strong wind pushes the box horizontally with a force of 25N. What is the acceleration of the box during this time?

  • Work time for assignment

Assignment

• • Pages 159 - 165

    • LT 12: Draw free body diagrams for all other problems

    • LT 13: For each, write out the Newton's 2nd law equations for the X and Y directions: Problems 2, 4, 6, 11

    • LT 14: Problems 41, 42, 46