MindsOn this slide is not intended to be shown in class Materials 2 sheets of paper 1 rubber ball Demo Take 2 identical sheets of paper Show students they are identical Crumple one sheet into a ball Hold out the ID: 573670
Download Presentation The PPT/PDF document "Lesson 3 – Acceleration Due to Gravity" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Lesson 3 – Acceleration Due to GravitySlide2
Minds-On
*this slide is not intended to be shown
in class
Materials: 2 sheets of paper, 1 rubber ball.
Demo: Take 2 identical sheets of paper. Show students they are identical. Crumple one sheet into a ball. Hold out the
uncrumpled
sheet in one hand and the crumpled one in the other. Ask students which will hit the ground first. Release both. Ask students why the crumpled sheet hit the ground first. Part 2: Take crumpled sheet in one hand and a rubber ball in the other. Show students the mass of the rubber ball is greater than the crumpled sheet. Ask them which will hit the ground first. Proceed to drop both (if sheet is crumpled sufficient, they should hit the ground simultaneously). Ask students why they hit the ground simultaneously even though the mass of the rubber ball is greater. Clickers hereSlide3
Acceleration Due to Gravity
Acceleration due to gravity (g) is the acceleration of an object falling vertically towards the Earth’s
surface
From observation, it would appear that objects fall to the earth at different rates (e.g. a paper ball and a piece of paper dropped from the same height do not hit the ground at the same time)
However, if air resistance is neglected, falling objects would only be affected by the earth’s gravity and they fall at the same rateSlide4
Acceleration due to Gravity -
Acceleration due to the earth’s gravity is quantified as:
Slide5
Around the Earth
Gravity on the earth is affected by the earth’s mass, radius, and oblate
shape
Thus,
gravity varies slightly depending on location. In general, the greater the distance from the Earth’s centre, the lower the acceleration due to gravitySlide6
Solving Gravity Problems
When calculating questions involving free fall one can simply use the five constant acceleration equations
(Big 5) for
uniformly accelerated motion that have been previously
presented
Example 1:
A ball is thrown directly up with a velocity of 12.1 m/s. Ignore air
resistance
What is the maximum height the ball will reach?How long does it take the ball to return to its maximum height & original position?Slide7
Solving Gravity Problems
What variables do we have?
(note that
in our example is the same as
)
What variable are we solving for?
Δ
So which equation should we choose?
Slide8
Which Equation to Use?Slide9
Solving the Equation
Rearrange equation to solve for
:
Slide10
Exit Ticket
What is acceleration due to gravity in m/s
2
on earth?
Why is gravity not exactly the same everywhere on earth?
Why do more massive objects not fall any faster than less massive objects?Slide11
Homework
Nelson Physics 12 Textbook (2001)
:
Questions 6 - 10