Lesson Plan

Period #6 Velocity vs Time Graphs / Acceleration of Gravity

Materials : Textbook : Physics - Principles and Problems

Return Velocity Quiz

Acceleration Worksheet

Acceleration and Velocity Review Sheet

Review : Go over Velocity Quiz

Mark questions 17 - 20 page 74 Practice Problems in Textbook

Objectives : students should be able to :

    1. use velocity-versus-time graphs to determine the instantaneous or average acceleration of objects
    2. solve problems for objects with constant acceleration, involving: displacement , initial velocity, final velocity, acceleration, time
    3. Define the Acceleration due to gravity
    4. solve problems for objects falling from rest
    5. solve problems for objects falling with an initial vertical velocity

 

Part I - Velocity vs Time Graphs - Introduction and Notes :

Review Notes starting at "Velocity-Time Graphs" p. 2-29, and discuss ways of calculating average and instantaneous acceleration.

Use overhead of graph on page 2-32 to demonstrate positive, negative and zero acceleration.

Use overhead of graph on page 2-33 to demonstate changing acceleration.

 

Guided Study :

Have students use overhead of graph on page 2-35, 2-36 to calculate average acceleration

Have students use overhead of graph on page 2-34 to calculate instantaneous acceleration.

Exercise :

Questions 5 - 8, page 68, Practice Problems in Textbook

Acceleration Worksheet

Acceleration and Velocity Review Sheet

Evaluation :

Acceleration Worksheet

Lab #3 - Measuring Acceleration

Acceleration Quiz

Unit Two Test

 

Part II - Acceleration Due to Gravity - Introduction and Notes

Give notes starting at "Acceleration Due To Gravity" p. 2-37, 2-38, and define the acceleration due to gravity and discuss how ‘g’ is dependant on the mass of a planet

Guided Study :

Do "Check Your Understanding" page 2-39 questions 1 and 2 - for question 2 state that horizontal velocity does not affect vertical velocity!

Exercise :

Questions 25, 27-29, page 77, 79, Practice Problems in Textbook

Evaluation :

Acceleration Quiz

Unit Two Exam

PROJECTILES - Vertical and Horizontal Motion are Independent

Vertical Direction
  • accelerates at 9.8 m/s/s downward
  • velocity changes by 9.8 m/s each second
  • distance traveled

d = viyt + ½ at2
  • where viy = the initial velocity in the downward direction, if the object starts from rest then viy is zero and

d = ½ at2

 

 

 

 

Horizontal Direction
  • NO acceleration

 

  • velocity is constant

 

  • distance traveled

d = vixt + ½ at2
  • vix is the initial horizontal velocity, since a = 0, and vix is constant :

 

d = vxt

 

 

 

 

 

 

 

 

 

 

Projectiles (Guided Study)
    1. A ball is thrown horizontally at 10.0 m/s. It is in the air for 5.0 seconds.

a) How far does it fall vertically?
    1. How far does it travel horizontally?
    2. How fast is it moving vertically just before it hits the ground?
    1. A bullet is fired horizontally at 300.0 m/s from a height of 2.00 m. How far does it go before it hits the ground?
    2. An arrow is shot straight up at 30.0 m/s. How long will it take for the trip?

 

Ans. 1a) 120 m b) 5.0 x 101 m c)49.0 m/s

      1. 192 m
      2. 6.10 s

Projectiles - Questions

  1. A car traveling at 72 km/h drives off a cliff 4.00 x 102 m high.

a) How long does it take to hit the ground?

b) How far from the base of the cliff does it land

c) How fast is its vertical component of velocity the instant it hits the ground?
  1. A baseball was hit out into centre field. It was in the air for 4.0 seconds. What was its maximum height?