10-28-08

So the day started out with a daily question (big Surprise) the question dealt with the homework from the night before. (notes 38-39) The homework problems consisted of making a "vt" graph and a LMD. Doing the discussion of the rocket, the number 9.8 m/s/s came up. We quickly learned that this number is the acceleration for an object in free fall. Well if the object is falling its -9.8 m/s/s. We then continued on in the packet and finished problems 11-17, all dealing with free fall. The free fall formula is, V2f =V2i + 2a∆X. (Final Velocity = Initial Velocity + 2 * 9.8 (free fall acceleration) distance object traveled.

Example: A stone starting at rest, falls 22 meters to the ground. How fast is it going just before it hits the ground?

V2 f =V2i + 2a∆X (Equation)

V2f = 02 +2(-9.8) ∙ -22 (Fill in values in the equation)

V2f = 431.2 (Solve the one side)

√v2f = √431.2 (Take the square root of both sides)

Vf = 20.7 m/s (Final answer)

Questions 11-17 are due for homework on 10-29-08.