Physics 1-2 (1st semester) A:Space, Time, and Motion; Unit 1 kinematics

What is physics?

Physics is a branch of science that studies matter, motion, and energy through both space and time.

This study’s main goal is to understand how the universe behaves.

What will be covered in the first semester?

Space, Time, and Motion & The Particulate Nature of Matter.

In the first semesters A: Space, Time, and Motion what three units do we cover?

1) Kinematics, 2) Forces and Momentum, and 3) Work, Energy, Power.

In the first semesters B: The Particulate Nature of Matter, what three units do we cover?

1) Thermal Energy Transfer, 2) The greenhouse Effect, 3) Gas Laws, and 4) Current and Circuits.

What are different units of measurement for things such as distance?

Inches, feet, yards, and miles, while the metric system's common units are millimeters, centimeters, meters, and kilometers.

When describing the motion of an object, what are 2–3 important ideas you need to include?

To describe the motion of an object, you must include its position, velocity, and acceleration.

Position and Distance; Definition and image to show you understand:

In physics, position is an object's specific location in space relative to a chosen reference point or frame of reference.

Displacement and Distance: Is there a difference between “displacement” and “distance”?

“Displacement” is how far out of place an object has moved; direction matters

“Distance” is how much an object has moved total

Displacement is a “vector” quantity

Is there such a thing as “negative” position?

Yes, an object can have a negative position in physics; it simply means the object is located in the direction that has been designated as negative within a chosen coordinate system, such as to the left of the origin on a number line.

What is Time?

Time only goes forwards; there is no such thing as “negative” time

This means time is NOT a vector; it is SCALAR

What are Vectors?

In physics, a vector is a physical quantity that has both magnitude (a numerical value representing size or amount) and direction.

What is Vector Addition?

Vector addition combines two or more vectors to find a single resultant vector representing their cumulative effect.

Notebook Problem #1

A man walks 95 m East, then walks an additional 15 m East

What is his overall displacement? Use notes

Final Answer: The man's overall displacement is 110 m East.

Notebook Problem #2

A man walks 45 m East, then turns around and walks 13 m West.

What is his overall displacement? Use notes

Final Answer: The overall displacement is 32 m East.

Notebook Problem #3 (part 1)

A man walks 30 m East, and then turns and walks 40 m to the South.

What is his overall displacement? Use Notes

Final Answer  The overall displacement is 50 m in the South-East direction.

Finding an angle. What do we use to do this?

SOHCAHTOA!

Review:

1. A bear, searching for food, wanders 35 meters east then 20 meters north.

Not finding any food, it wanders another 12 meters west then 6 meters south.

Calculate the bear’s final displacement.

Final Answer : The bear's final displacement is approximately 26.93 m.

Review:
2. A mountain climbing expedition establishes a base camp and two intermediate camps, A and B.

Camp A is 11,200 m east of and 3,200 m above base camp. Camp B is 8400 m east of and 1700 m higher than Camp A.

Determine the displacement between base camp and Camp B.

Final Answer: The displacement between base camp and Camp B is approximately 20203.22 m.

Review:

3. At exactly noon, an airplane is taking off from Malabo International Airport, located at the equator. The airplane reaches a take-off speed of 70 m/s due East.

At take-off, the plane ascends into the air at a 15˚ angle from the ground. Ground control is watching the runway during the plane’s takeoff, and watches the shadow of the plane on the runway below.

What is the velocity of the plane’s shadow on the runway?

Shadow Speed = Total Velocity * cos(15°)

Shadow Speed = 70 m/s * cos(15°)

Shadow Speed ≈ 70 m/s * 0.9659

Shadow Speed ≈ 67.6 m/s

Review:

4. A man is paddling in a canoe across a river. He knows that he’s able to paddle steadily at a pace of 5 m/s, but the current of the river is pushing his canoe downstream.

By the time he makes it to the other side of the river, he has drifted off course by 60o.

How fast is the river current?

The speed of the river current is approximately 8.66 m/s.

A canoe is paddling East across a 30 m wide river. If the river flows at 12 m/s, and the canoeist is paddling due East at 3 m/s, how far downstream will the canoe end up compared to where they started?

The canoe will end up 120 m downstream compared to where it started.