G9 Physics Lesson 1 1D Motion PDF

GRADE 9 SCIENCE 1ST TERM, SY 2024-2025 1D MOTION Teacher: Ms. Cherry Templonuevo Email: [email protected] Class Schedule:  TOPIC OUTLINE SHORT RECALL MOTI...

GRADE 9 SCIENCE 1ST TERM, SY 2024-2025 1D MOTION Teacher: Ms. Cherry Templonuevo Email: [email protected] Class Schedule:  TOPIC OUTLINE SHORT RECALL MOTION READING OF GRAPHS  REVIEW OF CONCEPTS Force (F) Net Force (Fnet) Acceleration (a) Mass (m) Vector Weight Gravity (Fg) Friction Normal Force (Fn) Speed Velocity  REVIEW OF CONCEPTS Matter- In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. It can be described in terms of its quality and quantity.  REVIEW OF CONCEPTS Quality -the characteristic or feature of something Quantity -refers to its amount or number  REVIEW OF CONCEPTS Scalar - is defined as the physical quantity that has only magnitude Vector - is defined as the physical quantity that has both magnitude as well as direction REVIEW OF CONCEPTS  REVIEW OF CONCEPTS Mass (m) - the amount of matter in material Weight - the measure of the amount of force acting on a mass due to acceleration due to gravity  REVIEW OF CONCEPTS Speed - is the rate of change of motion, i.e. distance moved by an object in a specified time irrespective of direction 40 kph Velocity - is the speed at which something moves in one direction 40 kph northwest  REVIEW OF CONCEPTS Scalar - is defined as the physical quantity that has only magnitude ex.: mass, speed Vector - is defined as the physical quantity that has both magnitude as well as direction ex.: weight, velocity  REVIEW OF CONCEPTS Examples of Forces: Gravity (Fg) Normal Force (Fn) Friction Force (Ff) Acceleration (a) - is the rate of change of the velocity of an object with respect to time  FORCE A force is a push or pull upon an object resulting from the object's interaction with another object.  FORCE AS A VECTOR force = m x a -is a vector quantity capable of producing motion -it has magnitude and direction -measured using the standard metric unit N or "newton" and a direction 1 Newton = force needed to move 1 kg of mass at an acceleration of 1 m/s2 Recall that forces are vectors! The direction matters.  NET FORCE IS THE SUM OF FORCES FROM ALL DIRECTIONS. If Fnet = 0, then a = 0, then there's no change in velocity. Motion is constant. If there is Net Force, then there is Acceleration, and there is WHAT'S THE NET change in velocity. There is change in motion. FORCE?  MOVING MAN SIMULATION https://phet.colorado.edu/sims/cheerpj/moving- man/latest/moving-man.html?simulation=moving-man Graphs of Motion, Position, Velocity WHAT IS MOTION?  TOPIC OUTLINE SHORT RECALL MOTION READING OF GRAPHS WHAT IS MOTION?  MOTION In physics, motion is the change in position of an object with respect to its surroundings in a given time It can be caused by the net force acting on the object. MOTION The motion of an object with some mass can be described in terms of the following: Distance Displacement Speed Velocity Time Acceleration KINDS OF MOTION One Dimensional Motion Two Dimensional Motion Three Dimensional Motion  1D MOTION In the figure shown below, a cart is moving from point A to point B. It is moving along a straight line (along the x-axis) with some velocity v. 1-DIMENSIONAL 1-DIMENSIONAL FREE-FALL MOTION Free-Fall  LINEAR MOTION It is a type of translational motion where the body moves in a single direction along a single dimension. 2-DIMENSIONAL 3-DIMENSIONAL DISTANCE VS DISPLACEMENT  WHAT IS SPEED? Speed is a measure of how fast an object moves. If an object moves from 1 position to another in a given time, its average speed v, is obtained by dividing the distance traveled by the time (t) taken to cover the distance. average speed = distance traveled time taken to cover the distance  WHAT IS AVERAGE SPEED? average speed = distance traveled time taken to cover the distance v=d/t the SI unit for speed is meter/second or m/s *Since this is average speed, this only considers the ratio of the total distance covered over time rather than the particular speed at a particular moment WHAT IS INSTANTANEOUS SPEED? A speedometer gives readings of instantaneous speed  WHAT IS AVERAGE SPEED? The speed of a body at a certain instance of time. It can be obtained by measuring the average speed over the shortest possible time interval as instantaneous varies from time to time. WHAT IS THE AVERAGE SPEED? A runner covered a distance of 100 meter in 10 seconds. What is the average speed of the runner?  WHAT IS AVERAGE SPEED? A runner covered a distance of Given: d = 100 m t = 10 s 100 meter in 10 seconds. What v=d/t is the average speed of the v =100 m / 10 s runner? v = 10 m/s GET THE SPEED! Get the speed of yourself walking.  WHAT IS VELOCITY? Velocity is speed in a given direction. It is defined as the rate of change in displacement. average velocity = total displacement time interval  SPEED AND VELOCITY 100 m/s South 100 m/s North The same speed but different velocity.  DISTANCE-TIME GRAPH A distance-time graph shows how far an object has travelled in a given time. It is a simple line graph that denotes distance versus time findings on the graph.  DISTANCE-TIME GRAPH UNDERSTANDING GRAPHS 1. What does x and y represent? 2. Where does the value increase or decrease? 3. What are the data plotted in the graph? 4. Relate x and y to the given graph... when the line is a) going up, b) constant and c) going down?  DISTANCE-TIME GRAPH A distance-time graph shows how far an object has travelled in a given time. It is a simple line graph that denotes distance versus time findings on the graph. 1. Distance is plotted on the Y-axis. 2. Time is plotted on the X-axis.  DISTANCE-TIME GRAPH A bus driver drives at a constant speed which is indicated by the speedometer and the driver measures the time taken by the bus for every kilometre. The driver notices that the bus travels 1 kilometre every 2 minutes until it covered 7 kilometers. DISTANCE-TIME GRAPH The graph is a straight line and the motion of the bus is also uniform. Also, from the graph, we can find the speed of the bus at any instant of time. The initial and final position of the car can be found as the following: Speed = (Final Position-Initial position) Time  DISTANCE-TIME GRAPH A bus driver drives at a constant speed which is indicated by the speedometer and the driver measures the time taken by the bus for every kilometre. The driver notices that the bus travels 1 kilometre every 2 minutes. Speed = (Final Position-Initial position) Time To get the average distance from the initial point to 1 km, it can be obtained by: Speed = (Final Position-Initial position) = 1 km -0 km = 0.5 km Time 2 min min  DISTANCE-TIME GRAPH Distance Speed A bus driver drives at a constant speed which is indicated by the speedometer and the driver measures the time taken by the bus for every kilometre. The driver notices that the bus travels 1 kilometre every 2 minutes. Time = (Final Position-Initial position) Ave. Speed What if I want to know how long will it take me to reach the 7 km point, how would I know? Time = (Final Position-Initial position) = 7 km -0 km = 14 mins Ave. Speed 0.5 km/min  EXERCISES 1.)40 km 2 hrs 2.)180 km 3.)180 km 1.5 hrs 3 hrs  EXERCISES 1. An airplane flies with a constant speed of 880 km/h. How far can it travel in 1 1/2 hours? 2. An airplane flies with a constant speed of 800 miles per hour. How long will it take to travel a distance of 2800 miles? 3. An airplane flies with a constant speed of 820 miles per hour. How long will it take to travel a distance of 3280 miles?  EXERCISES 4. Grace roller skates with a constant speed of 18 km/h. How long will she take to travel a distance of 63 kilometers? 5. A taxi hurries with a constant speed of 50 miles per hour. How far can it travel in 1/2 hour? 6. A car drives with a constant speed of 32 miles per hour. How long will it take to travel a distance of 80 miles?  WHAT IS ACCELERATION? Acceleration is a vector quantity as it has both magnitude and direction. It is also defined as the as the rate at which an object changes its velocity. An object is accelerating if it is changing its velocity. acceleration = final velocity - initial velocity time interval  WHAT IS ACCELERATION? acceleration = final velocity - initial velocity time interval Where, a is the acceleration in m/s 2 acceleration = vf - vi t vf is the final velocity in m/s vi is the initial velocity in m/s a= v t is the time interval in s t Δv is the small change in the velocity in m/s  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to 100 m/s. The new Ferrari can achieve this in 5 s. What is the average acceleration of the car in m/s?  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to 100 m/s. The new Ferrari can achieve this in 5 s. What 2 is the average acceleration of the car in m/s? Given: vi= 0 vf = 100 m/s t = 5s 2 Find the: acceleration in m/s  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to 100 m/s. The new Ferrari can achieve this in 5 s. What is the average acceleration of the car in m/s? Given: vi= 0 vf = 100 m/s t=5s 2 Find the: acceleration in m/s Solution: a = vf - vi = 100 m/s - 0 m/s change in t 5s  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to 100 m/s. The new Ferrari can achieve this in 5 s. What is the average acceleration of the car in m/s? Given: v1= 0 v2 = 100 m/s t=5s 2 Find the: acceleration in m/s Solution: a = vf - vi = 100 m/s - 0 m/s = 20 m/s2 change in t 5s  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to a certain velocity. The new Ferrari can achieve this in 5 s. What is the target final velocity of the car if the acceleration is 20 m/s2 ?  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to a certain velocity. The new Ferrari can achieve this in 5 s. What is the target final velocity of the car if the acceleration is 20 m/s2 ? 2 Given: vi= 0 t=5s a = 20 m/s Find the: vf Solution:  WHAT IS ACCELERATION? acceleration = final velocity - initial velocity time interval Where, a is the acceleration in m/s 2 acceleration = vf - vi t vf is the final velocity in m/s vi is the initial velocity in m/s a= v t is the time interval in s t Δv is the small change in the velocity in m/s HOW TO SOLVE FOR THE FINAL VELOCITY? acceleration = final velocity - initial velocity time interval acceleration = vf - vi t HOW TO SOLVE FOR THE FINAL VELOCITY? acceleration = final velocity - initial velocity time interval acceleration = vf - vi t a x t = vf - vi HOW TO SOLVE FOR THE FINAL VELOCITY? acceleration = final velocity - initial velocity time interval acceleration = vf - vi t a x t = vf - vi + vi +vi (a x t) + vi = vf HOW TO SOLVE FOR THE FINAL VELOCITY? acceleration = final velocity - initial velocity time interval IF THE OBJECT STARTS acceleration = vf - vi FROM REST: t vf = (a x t) + 0 =axt a x t = vf - vi + vi +vi (a x t) + vi = vf vf = (a x t) + vi  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to a certain velocity. The new Ferrari can achieve this in 5 s. What is the target final velocity of the car if the acceleration is 20 m/s2 ?  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to a certain velocity. The new Ferrari can achieve this in 5 s. What is the target final velocity of the car if the acceleration is 20 m/s2 ? 2 Given: vi= 0 t=5s a = 20 m/s Find the: vf Solution: vf = (a x t) + vi = (20 m/s x 5 s) + 0 m/s  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to a certain velocity. The new Ferrari can achieve this in 5 s. What is the target final velocity of the car if the acceleration is 20 m/s2 ? 2 Given: vi= 0 t=5s a = 20 m/s Find the: vf Solution: vf = (a x t) + vi = (20 m/s x 5 s) + 0 m/s = 100 m/s HOW TO SOLVE FOR THE INITIAL VELOCITY? acceleration = final velocity - initial velocity time interval acceleration = vf - vi a x t = vf - vi t - vf -vf (a x t) - vf = -vi -vi = (a x t) - v a x t = vf - vi + vi +vi (a x t) + vi = vf vf = (a x t) + vi HOW TO SOLVE FOR THE INITIAL VELOCITY? acceleration = final velocity - initial velocity time interval acceleration = vf - vi a x t = vf - vi t - vf -vf IF THE OBJECT (a x t) - vf = -vi vi = vf - (a x t) COMES TO A STOP: -vi = (a x t) - 0 -vi = (a x t) vi = -(a x t)  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to 100 m/s. What is the time taken by the new Ferrari to 2 reach the target final velocity of the car if the acceleration is 20 m/s ? Given: vi= 0 vf = 100 m/s a = 20 m/s2 Find the: t Solution:  HOW TO SOLVE FOR THE TIME? acceleration = final velocity - initial velocity time interval acceleration = vf - vi t a x t = vf - vi ( a x t = vf - vi ) / a t = vf - vi a  EXERCISES 1. A car's performance is often assessed by the shortest time required to accelerate it from rest to 100 m/s. What is the time taken by the new Ferrari to 2 reach the target final velocity of the car if the acceleration is 20 m/s ? Given: vi= 0 vf = 100 m/s a = 20 m/s2 Find the: t Solution: t = vf - vi = 100 m/s - 0 = 5 s a 20 m/s 2 HOW TO SOLVE FOR THE FINAL DISTANCE? d= ave. v x t t = vf - vi a d = vf + vi (vf - vi) 2 a 2 2 d= vf - vi 2a  EXERCISES 1. A poorly tuned Geo Metro can accelerate from rest to a speed of 28 m/s in 20 s. a. What is the average acceleration of the car? 2. At t = 0 a car has a speed of 30 m/s. At t = 6 s its speed is 14 m/s. What is its average acceleration during this time interval? TYPES OF ACCELERATION TYPES OF ACCELERATION  EXERCISES 1. A train travelled from Bristol to Bath. The train started from rest, and accelerated for 3 minutes to a speed of 46 km/h. The train then stayed at 46 km/h for 20 minutes. The train then decelerated for 4 minutes and came to a stop. Use the information to draw a velocity-time graph on the axis below. Assume all accelerations and decelerations are linear.  EXERCISES 2. The velocity-time graph below shows the journey of a car. (a) Use the graph to estimate the speed of the car after 30 hours. (b) Use the graph to find the acceleration of the car between 20 and 40 hours. (hours)  SEATWORK 1. Alice went for a bike ride. She started from rest and accelerated for 8 seconds to a speed of 11 metres per second. She then stayed at 11 metres per second for a further 16 seconds. She then accelerated again for 6 seconds to a speed of 14 metres per second. She then stayed at 14 metres per second for a further 18 seconds. She then decelerated, coming to a stop after 12 seconds. Use the information to draw a velocity-time graph on the axis below. Assume all accelerations and decelerations are linear.  SEATWORK 2. The velocity-time graph below shows the run of a sprinter. (a) Use the graph to find the sprinter’s acceleration between 0 and 20 seconds. (b) Use the graph to estimate the sprinter’s speed after 8 seconds. (c) During which period was the sprinter’s speed constant? DID WE MEET OUR GOALS? TELL THE DIFFERENCE BETWEEN SPEED AND VELOCITY DEFINE ACCELERATION DISCUSS THE GRAPHICAL REPRESENTATION OF MOTION SOLVE LINEAR MOTION PROBLEMS  THANK YOU AND WHAT QUESTIONS DO YOU HAVE? [email protected]