Objective: Students will continue practicing the concepts behind projectile motion.  They will begin problem solving.

Guided Practice: Students will be allowed a few minutes at the beginning of class for group work on problems assigned from the previous day: Giancoli problems 19, 20, 24.

Problem 19. A tiger leaps horizontally from a 7.5-m-high rock with a speed of 4.5 m/s.  How far from the base of the rock will she land?
Problem 20. A diver running 1.6 m/s dives out horizontally from the edge of a vertical cliff and reaches ther water below 3.0 s later.  How high was the cliff and how far from the base did the diver hit the water?
Problem 24. A ball is thrown horizontally from the roof of a building 56 m tall and lands 45 m from the base.  What was the ball's initial speed?

Modeling: The teacher will present solutions to the Giancoli problems the students have been working on.

Demonstration: The teacher will launch a ball bearing from a known height on the table.  The ball will return to the same height on the table and using the equations of motion the teacher and students will predict the elapsed time for the flight of the ball bearing.  The teacher will then demonstrate that we do in fact confirm the predicted elapsed time.

Independent Practice: 2 Dimensional Problems from Giancoli: 27, 28, 36.

Problem 27. A ball thrown horizontally at 22.2 m/s from the roof of a building lands 36.0 m from the base of the building.  How high is the building?

Problem 28. A shot-putter throws the shot with an initial speed of 14 m/s at a 40º angle to the horizontal.  Calculate the horizontal distance traveled by the shot if it leaves the athlete's hand at a height of 2.2 m above the ground.

Problem 36. A projectile is shot from the edge of a cliff 125 m above ground level with an initial speed of 105 m/s at an angle of 37.0º with the horizontal, as shows in the figure.  (a) Determine the time taken by the projectile to hit point P at ground level. (b) Determine the range X of the projectile as measured from the base of the cliff.  At the instant just before the projectile hits point P, find (c) the horizontal and vertical components of its velocity, (d) the magnitude of the velocity, and (e) the angle made by the velocity vector with the horizontal.
 
 
 

*Problems are taken from Giancoli's PHYSICS, Fifth Edition. Prentice Hall, New Jersey: 1998.