First semester exam
PHYSICS
You'll solve speed and velocity questions and be expected to know the difference between the two. The fact that the terms are often used interchangeably should not confuse you. Remember that students get velocity and acceleration problems confused because of similarity in variables. They both contain Distance and Time but an acceleration problem has an additional Time variable.
Velocity: Distance per Time
Acceleration: Distance per Time per Time
Acceleration problems take many forms but in each you have to be able to use available data to complete calculations for an unknown.
You'll be required to use the equations A=Vf-Vi /t as well as d=1/2at2
Of course; depending on the variable provided you’ll have to do a little algebra. Or; use the magic pyramid of simplicity.
There will be a couple of “Harry Problems” on the test.
You’ll have to calculate his landing point based on the height of the building and his running speed. Start by figuring out how much time he’ll spend falling. Then use his horizontal velocity, and that falling time, to determine the total horizontal distance he’ll travel.
You’ll also be required to calculate the height of a building based on a landing point provided. If you know how fast Harry is running and you know where he lands you can calculate how long Harry was falling. If you know how long Harry was falling and you know his acceleration due to gravity, you can determine the height from which he fell.
Horizontal motion is independent of vertical motion.
Provide an example.
Don’t get trapped thinking that all acceleration problems involve gravity. You know acceleration due to gravity is 9.8 if you’re showing off and 10 if you’re rounding off.
In free-fall velocity changes and acceleration does not.
Calculate Momentum. Mom = mass x velocity.
If you’re going to compare the momentum of two objects you’ve got to “do the math” first. Momentum explains why being hit by a football player moving real slow is about the same as being hit by a baseball moving real fast. Try it:
Momfbp = 120 kg x .05 m/s The momentum of a big football player moving slow is 6 kg/m/s and that momentum will be transferred to you in a collision.
Mombb = .145 kg x 42m/s The momentum of a baseball moving fast is 6 kg/m/s and that momentum will be transferred to you in a collision.
You’ll use the conservation of momentum to solve collision problems. We’ll use inelastic collisions for these problems so two objects with initial separate momentums will collide and join (remember Granny and Ambrose) and they’re momentum, now combined, after the collision will be equal to the momentum before.
Solve vector problems using:
Pythagorean Theorem when vectors are at 90 degrees.
Addition and Subtraction when vectors are 0 and/or 180 degrees
Parallelogram Rule when vectors are at any other angles than above.
First Law of Motion, Newton’s First Law, The Law of Inertia; all describe a resistance to acceleration. A resistance to change.
The Second Law is usually stated as an equation
F = M x A. Use of the equation confirms that 1 newton of force applied to 1 kg of mass will produce an acceleration of 1 m/s/s.
The Third Law of Motion is the Action / Reaction Law. Actions occur in pairs and are equal.
Work is a product of Force and Distance. It is measured in joules which is the unit of energy. Work is an expression of energy. One Joule of Work is done when 1 Newton of force moves an object 1 Meter. W=FxD
If an object is raised 1 meter by exerting 1 newton of force, the object will possess, or store, 1 joule of Gravitational Potential Energy. If that object is released the Potential Energy will be converted to Kinetic Energy.
Distinguish between Mass and Weight. Mass is a measure of inertia and is determined by the amount of matter that makes up the object. Weight is a measure of gravitational force between objects.
You'll solve speed and velocity questions and be expected to know the difference between the two. The fact that the terms are often used interchangeably should not confuse you. Remember that students get velocity and acceleration problems confused because of similarity in variables. They both contain Distance and Time but an acceleration problem has an additional Time variable.
Velocity: Distance per Time
Acceleration: Distance per Time per Time
Acceleration problems take many forms but in each you have to be able to use available data to complete calculations for an unknown.
You'll be required to use the equations A=Vf-Vi /t as well as d=1/2at2
Of course; depending on the variable provided you’ll have to do a little algebra. Or; use the magic pyramid of simplicity.
There will be a couple of “Harry Problems” on the test.
You’ll have to calculate his landing point based on the height of the building and his running speed. Start by figuring out how much time he’ll spend falling. Then use his horizontal velocity, and that falling time, to determine the total horizontal distance he’ll travel.
You’ll also be required to calculate the height of a building based on a landing point provided. If you know how fast Harry is running and you know where he lands you can calculate how long Harry was falling. If you know how long Harry was falling and you know his acceleration due to gravity, you can determine the height from which he fell.
Horizontal motion is independent of vertical motion.
Provide an example.
Don’t get trapped thinking that all acceleration problems involve gravity. You know acceleration due to gravity is 9.8 if you’re showing off and 10 if you’re rounding off.
In free-fall velocity changes and acceleration does not.
Calculate Momentum. Mom = mass x velocity.
If you’re going to compare the momentum of two objects you’ve got to “do the math” first. Momentum explains why being hit by a football player moving real slow is about the same as being hit by a baseball moving real fast. Try it:
Momfbp = 120 kg x .05 m/s The momentum of a big football player moving slow is 6 kg/m/s and that momentum will be transferred to you in a collision.
Mombb = .145 kg x 42m/s The momentum of a baseball moving fast is 6 kg/m/s and that momentum will be transferred to you in a collision.
You’ll use the conservation of momentum to solve collision problems. We’ll use inelastic collisions for these problems so two objects with initial separate momentums will collide and join (remember Granny and Ambrose) and they’re momentum, now combined, after the collision will be equal to the momentum before.
Solve vector problems using:
Pythagorean Theorem when vectors are at 90 degrees.
Addition and Subtraction when vectors are 0 and/or 180 degrees
Parallelogram Rule when vectors are at any other angles than above.
First Law of Motion, Newton’s First Law, The Law of Inertia; all describe a resistance to acceleration. A resistance to change.
The Second Law is usually stated as an equation
F = M x A. Use of the equation confirms that 1 newton of force applied to 1 kg of mass will produce an acceleration of 1 m/s/s.
The Third Law of Motion is the Action / Reaction Law. Actions occur in pairs and are equal.
Work is a product of Force and Distance. It is measured in joules which is the unit of energy. Work is an expression of energy. One Joule of Work is done when 1 Newton of force moves an object 1 Meter. W=FxD
If an object is raised 1 meter by exerting 1 newton of force, the object will possess, or store, 1 joule of Gravitational Potential Energy. If that object is released the Potential Energy will be converted to Kinetic Energy.
Distinguish between Mass and Weight. Mass is a measure of inertia and is determined by the amount of matter that makes up the object. Weight is a measure of gravitational force between objects.
getting ready for physics
We'll begin the school year studying motion. We'll observe and measure relative motion, speed, and acceleration in our first few days of class. We'll use basic algebra. Lots and lots of basic algebra.
Begin with these few tips.
1. On day one have a notebook that is dedicated to Physics and only Physics.
I like a small three ring binder with pockets. You'll definitely want something with
pockets.
2. Read the safety contract. It is mostly common sense but I need to know that we are all thinking about safety first. You'll find the contract under the
Staying Up-To-Date Tab.
3. If your algebra skills are rusty, take a look at these short video clips. They are very basic lessons but I've had a lot of students fall behind because their algebra skills had gotten rusty.
a. Solving Equations #1
b. Solving Equations #2
Begin with these few tips.
1. On day one have a notebook that is dedicated to Physics and only Physics.
I like a small three ring binder with pockets. You'll definitely want something with
pockets.
2. Read the safety contract. It is mostly common sense but I need to know that we are all thinking about safety first. You'll find the contract under the
Staying Up-To-Date Tab.
3. If your algebra skills are rusty, take a look at these short video clips. They are very basic lessons but I've had a lot of students fall behind because their algebra skills had gotten rusty.
a. Solving Equations #1
b. Solving Equations #2