Physical Science (Unit of Motion Test)

 Distance/Time slope:Speed

Distance/velocity slope:Acceleration



Distance:

Calculate and add all movement in all directions

 2 miles north + 7 miles west=9 miles in distance



Displacement: 

Find the hypotenuse of the 2 points if it makes a triangle


To calculate: 

 

22+72=?2


49+4=53


537.04



                                                                              Rate of change


                                                                               






Speed

  • Definition: Speed is a scalar quantity that measures how fast an object is moving, regardless of its direction (The motion of objects)

Velocity

  • Definition: Velocity is a vector quantity that measures the rate of change of an object's position, including both speed and direction. (Speed with Direction)

How do you find speed?

Speed=DistanceTime

Problem: If Sam and Thomas drive 200 miles in 2.5 hours to visit their mom, how fast were they going?
case, the distance is 200 miles and the time is 2.5 hours. Plugging in the values:



So, Sam and Thomas were driving at a speed of 80 miles per hour.


  • We can also adjust the speed formula to solve for time.

Probem: If a car is moving 50 mi/hr and travels 30 miles, how long did the journey take?

To find the time taken for the journey, you can use the formula:


In this case, the distance is 30 miles and the speed is 50 miles per hour. Plugging in the values:









1. Two pieces of information for navigation

To get from one location to another, you need to know:

  • The starting point (location): Where you are beginning your journey.

  • The destination (location): Where you want to go.

2. Difference between distance and position

  • Distance refers to the total length of the path traveled between two points, regardless of direction. It is a scalar quantity and is always positive.

  • Position refers to a specific point in space relative to a reference point, often expressed as coordinates. It is a vector quantity that includes direction.

3. Current position after walking

Starting at the origin (0 meters):

  • Walk 3 meters east: 0+3=30 + 3 = 30+3=3 meters.

  • Walk 7 meters west: 3−7=−43 - 7 = -43−7=−4 meters.

  • Walk 6 meters east: −4+6=2-4 + 6 = 2−4+6=2 meters.

You are now 2 meters east of the origin.

4. Examples of describing position

a. One dimension: A train is 50 meters down the track from the station. (Position along a single line)

b. Two dimensions: A park is located at coordinates (3, 4) on a map. (Position on a flat surface)

c. Three dimensions: A drone is flying at coordinates (2, 5, 10) meters above the ground in a 3D space. (Position in space)

5. Movie theater coordinates

Using your house as the origin (0, 0): d. The coordinates of the movie theater, which is 4 kilometers east and 2 kilometers south, are (4, -2).

e. After driving 5 kilometers west and 3 kilometers north from the movie theater:

  • Starting from (4, -2):

    • Move 5 km west: 4−5=−14 - 5 = -14−5=−1

    • Move 3 km north: −2+3=1-2 + 3 = 1−2+3=1

The coordinates of the restaurant are (-1, 1).

6. Origin of an object

No, the origin of an object does not always have to be at zero on a number line or x-y plane. The origin can be defined arbitrarily based on the context of a problem. For example, you might choose a point of interest as the origin (like your house), and all positions would be relative to that point, even if it’s not at (0,0). This flexibility allows for more convenient calculations in different scenarios.








1. Constant speed and distance per second

If something moves at a constant speed, it covers the same distance each second. For example, if it moves at 10 meters per second, it will cover 10 meters in each second consistently.

2. Difference between speed and velocity

  • Speed is a scalar quantity that measures how fast an object is moving, regardless of its direction. It is expressed as distance per unit of time (e.g., km/h).

  • Velocity is a vector quantity that includes both the speed of an object and the direction in which it is moving. For example, 50 km/h north is a velocity, while 50 km/h is just a speed.

3. Path of a ball rolling with constant velocity

If a ball rolls along the ground at a constant velocity, it follows a straight path in a consistent direction without speeding up, slowing down, or changing direction.

____















1. Slope of a position versus time graph

The slope of the line on a position versus time graph represents the speed of the object. A steeper slope indicates a higher speed, while a flatter slope indicates a lower speed. If the slope is positive, the object is moving in a positive direction; if it's negative, the object is moving in the opposite direction.

2. X-values and Y-values on a position versus time graph

  • X-values (horizontal axis) represent time. This indicates how long the object has been moving.

  • Y-values (vertical axis) represent position. This indicates the location of the object at a given time.

4. Faster speed from a graph

To determine which runner has the faster speed from a position versus time graph, look at the slopes of their lines:

  • The runner with the steeper slope has the faster speed.

  • If one line rises more quickly than another over the same time interval, that runner is moving faster.

6. Maria's walking motion

a. Speed versus time graph for Maria's motion

  • Since Maria walks at a constant speed of 2 m/s for 8 seconds, the graph would be a horizontal line at 2 m/s from time 0 to 8 seconds, and then it would stop.

b. How far does she walk? To find the distance she walks, use the formula:

So, Maria walks 16 meters.


Force(F) Push or pull one object exerts on another.

  • Measured in Newtons (1N=1k*m/s2)

  • Forces can cause a change in an object’s motion

  • More than one force can act on an object at one point

Forces on an object can be balanced or unbalanced

  • Balanced Forces: The sum of the forces=0

Newton's First law: Law of inertia/System cannot accelerate itself

An object will move at a constant velocity until a net force acts on it

NOTHING CAN ACCELERATE ITSELF!!

  • Thing accelerate one to systems interact

Ⅰ. The rougher the surface, the greater the friction

Ⅱ. The greater the force pushing the two objects together, the greater the friction


Ⅲ. Static Friction(Kinetic Friction): A force between to object that prevents them from moving 

Quiz: Motion and Velocity

Question 1:

If a car travels 200 miles in 4 hours, what is its average speed?

Answer: 50 miles per hour

Question 2:

What is the slope of a position versus time graph?

Answer: Velocity

Question 3:

If a ball is thrown vertically upward, what is its acceleration at its highest point?

Answer: 0 m/s²

Question 4:

A car is traveling at a constant speed of 30 miles per hour. What is its acceleration?

Answer: 0 miles per hour per second

Question 5:

If an object is at rest, what is its acceleration?

Answer: 0 m/s²

Question 6:

What is the formula for calculating acceleration?

Answer: Acceleration = (Final Velocity - Initial Velocity) / Time

Question 7:

If a car accelerates from 0 to 60 miles per hour in 5 seconds, what is its average acceleration?

Answer: 12 miles per hour per second

Question 8:

What is the difference between a scalar quantity and a vector quantity?

Answer: A scalar quantity has magnitude only, while a vector quantity has both magnitude and direction.

Question 9:

Which of the following is a vector quantity?

Answer: Velocity

Question 10:

If a car is traveling north at a constant speed of 50 miles per hour, what is its velocity?

Answer: 50 miles per hour north

Question 11:

If a car accelerates from 0 to 30 m/s in 5 seconds, what is its average acceleration?

Answer: 6 m/s²

Question 12:

A ball is thrown upward with an initial velocity of 20 m/s. What is its velocity at the highest point?

Answer: 0 m/s

Question 13:

What is the formula for calculating distance from velocity and time?

Answer: Distance = Velocity * Time

Question 14:

If a car is traveling at a constant velocity, what is its acceleration?

Answer: 0 m/s²

Question 15:

What is the difference between a scalar quantity and a vector quantity?

Answer: A scalar quantity has magnitude only, while a vector quantity has both magnitude and direction.

Question 16:

Which of the following is a vector quantity?

Answer: Velocity

Question 17:

If a car is traveling north at a constant speed of 50 miles per hour, what is its velocity?

Answer: 50 miles per hour north

Question 18:

If a ball is thrown upward with an initial velocity of 20 m/s, what is its acceleration at its highest point?

Answer: 9.8 m/s² downward

Question 19:

What is the formula for calculating acceleration?

Answer: Acceleration = (Final Velocity - Initial Velocity) / Time

Question 20:

If a car accelerates from 0 to 30 m/s in 5 seconds, what is its average acceleration?

Answer: 6 m/s²


QUIZ ZIP:

Question 1:

What is the difference between distance and displacement?

Answer: Distance is the total path traveled; displacement is the shortest path from start to finish.

Question 2:

Which of the following best describes average speed?

Answer: The total distance divided by the total time

Question 3:

If a car travels 100 meters north and then 100 meters south, what is the displacement?

Answer: 0 meters

Question 4:

Which of the following represents an object's velocity?

Answer: 30 miles per hour to the east

Question 5:

Which of the following distance vs time gr aphs represents a constant non-zero speed?

Answer: A straight diagonal line

Question 6:

Which of the following statements is true regarding a velocity versus time graph?

Answer: All of the above.

Question 7:

If an object is moving in a circular path at a constant speed, it is:

Answer: Changing velocity

Question 8:

A distance-time graph shows a line that slopes upward. What does this indicate?

Answer: The object is moving away from the starting point.

Question 9:

What is the formula for calculating speed?

Answer: Speed = Distance × Time

Question 10:

Which of the following are Vectors?

Answer: Velocity and Displacement

terminal velocity, steady speed achieved by an object freely falling through a gas or liquid. 


NOTES CON.


  • Friction: Resistance to motion when two objects are in contact with one another

  • Air resistance:Resistance an object feels when traveling through the air

  • Gravity: The attraction two objects have on one another m




















More force on one side versus the other


F=ma

Is gravity an action because its a force? So does gravity makes us fly?
Because it like as an opposite reaction on a surface like humans

Fnet= Net forces


Fnet=MA

Fnet= T-MA



Collisions:

The main types of collisions are elastic, inelastic, and perfectly inelastic:

  • Elastic collision

  • Both kinetic energy and momentum are conserved, and the objects bounce away from each other. A perfectly elastic collision is rare.

  • Inelastic collision

  • Only momentum is conserved, and the objects do not bounce away from each other or may stick together. 

Collisions are a common way to test understanding of momentum in physics. Momentum is the product of an object's mass and velocity. In all collisions, momentum is conserved without external forces. 

Other types of collisions include head-on collisions and oblique collisions: 

  • Head-on collision

  • A specific type of frontal impact collision that occurs when the front ends of two vehicles collide. 

  • Oblique collision

  • A multidimensional collision where the two objects collide from different angles. 

QUIZ:

  1. The speed you read on a speedometer is:

Instantaneous speed

  1. 3m/s north is an example of______

Velocity

  1. A car moves around a wide turn going 45 mi/hr the whole time. The car has a constant_______

Speed

  1. If you ride your bicycle down a straight road for 500m the turn around and ride back to your starting point, your distance is _____ your displacement

Greater than

  1. An object in motion must be undergoing a change of_____

Position

  1. A softball pitcher throws a ball 42 m/s/ If the batter is 18m form the pitcher, approx. how much time does it take for the ball to reach the batter

0.43 s