460 likes | 471 Views
Speed and Velocity Notes. Flashback Questions: Types of Rocks. 1. What type of rocks form beneath the Earth’s surface? 2. What type of rocks form on the inside of volcanoes (magma)? 3. What type of rocks form near bodies of water?
E N D
Flashback Questions: Types of Rocks • 1. What type of rocks form beneath the Earth’s surface? • 2. What type of rocks form on the inside of volcanoes (magma)? • 3. What type of rocks form near bodies of water? • 4. What type of rocks form on the outside of volcanoes (lava)? • 5. What type of rock has fossils in them?
Motion occurs when there is a change in positionof an object with respect to a reference starting point. ● The final position of an object is determined by measuring the change in position (Motion) and direction of the segments along a trip.
What is Motion A change in position
The following terms are used to describe and determine motion:
Position Position is the location of an object. An object changes position if it moves relative to a reference point (starting point).
Distance Vs. Displacement Distance is how far an object travels. Ex: _____ Displacement the distance and direction of an object’s change in position from the starting point (displacement). Ex:_______
Ticket Out the Door/Reinforcement Activity Sheet Block 24 Block 3 What is the beginning position of the bus? ____________ What is the ending position of the bus? ___________ What is the direction of the bus? ______________ What is the distance the bus travelled? _______________ blocks
Displacement A displacement includes both the distance and a direction. Examples of Displacements: - 10 m north - 23 m left - 15 m down Question: How do you know these are displacements?
Displacement Displacement = distance + direction 10 m left So what is the main difference between distance and displacement?
For example, given the following data table, determine the change in the object’s position based on its final position, distance, and direction, from a starting point.
Give the distance and Displacement for X, Y, Z from previous chart.
Direction Direction is the line, or path along which something is moving, pointing, or aiming. Direction is measured using a reference point with terms such as up, down, left, right, forward, backward, toward, away from, north, south, east, or west.
Speed Speed is a measure of how fast something moves a particular distance (for example, meters) over a given amount of time (for example, seconds). Speed does not necessarily mean that something is moving fast.
SPEED SLOPE -The slope of the line can tell the relative speed of the object. -When the slope of the line is steep, the speed is faster -When the slope of the line is flatter, the speed is slower. -When the slope of the line is flat, horizontal to the x-axis, the speed is zero (no movement)
Position-Time Graphs • A graph used to show a change in an object’s location over time. • TIME: the _______________________ variable - is plotted on the x-axis and • POSITION/DISTANCE: the __________________________variable - is plotted on the y-axis.
Speed vs. Velocity SPEED How much time it takes for an object to move or change position Speed formula: v=d/t (d = total distance) INCLUDES DISTANCE AND TIME
Speed vs. Velocity VELOCITY How quickly an object moves or changes direction WITH REFERENCE to a particular direction Velocity formula: v= d/t (d = total displacement) INCLUDES SPEED (DISTANCE & TIME) AND DIRECTION
Calculating Speed Average speed can be calculated by dividing the total distance the object travels by the total amount of time it takes to travel that distance. Constant speed will have the same speed throughout.
AVERAGE SPEED Average speed can be calculated by the formula: v = d/t ORTotal distance the object travelsTimeto travel the distance
Speed of an object can change while travelling SO the average speed takes the totaldistance divided by the time travelled EX) Think of a bus going through town to pick up students. It speeds up, slows down, and stops several times. Even though it’s speed is changing the entire trip, to find average speed we would only need to know the total distance the bus travelled and how long it took for the bus to get there
Because speed is made up of distance units divided by time units, some examples of speed units are “meters per second” (m/s), “kilometers per hour” (km/h), or “miles per hour” (mph or mi/hr).
Velocity refers to both the speed of an object and the direction of its motion. Therefore, velocity value will have both speed units and direction units, Examples include: m/sec north, km/h south, cm/s left, or km/min down.
● If an object is moving forward, it haspositive velocity. ● If an object is moving backwards, it hasnegativevelocity. For example: When you throw a ball in the air, it has positive velocity. When it heads back towards you, it has negative velocity.
Average Velocity is calculated using v = d/tOR Total Displacement Total Time
The total displacement is the distance and direction from the starting point The average velocity MUST have the same direction as the total displacement *****Total displacement may be different than total distance
Distance-Time graph This distance-time graph can then be used to describe the speed of the object. For example, the speed of segment A is slower than segment C. The speed of segment B is zero, the object is not moving.
PRACTICE TIME EXAMPLE: A train travels 100 km in 2 hours with a total displacement of 50 km. Calculate the average speed of the train Average Speed = Total distance = __________________ = Total time = Calculate the average velocity of the train Average Velocity =Total displacement = __________________ = Total time =
SUMMARY: In 2 sentences, give one difference and one similarity between speed and velocity
PRACTICE FIND TOTAL DISTANCE AND DISPLACEMENT for both lines
Calculation SPEED 1. What is the speed of a sailboat that is traveling 100 meters in 120 seconds? 2. If a cyclist in the Tour de France traveled southwest a distance of 12,250 meters in one hour, what would the velocity of the cyclist be?
1. Calculate the speed of a dog running through a field if he is covering 23.7 meters in 54 seconds. 2. If a cross country runner covers a distance of 347 meters in 134 seconds what is her speed? 3. What is the speed of a baseball that travels 49 meters in 2.4 seconds?
4. What is the speed of a horse in meters per second that runs a distance of 1.2 miles in 2.4 meters? 5. Calculate the velocity of a car that travels 556 kilometers northeast in 3.4 hours. Leave your answer in kilometers per hour.
6. If the distance covered by a jogger is 2,541meters through the park and the time it took to cover that distance was 43.6 minutes, what was the speed of the jogger? 7. Which object has a greater velocity, a ball rolling down a 3.4 meter hill in six seconds or a fish swimming upstream and covering 5.4 meters in 0.4 minutes?
8. If Seneca decides to walk across town to a store that is .95 kilometers away and she has only 25 minutes to get there, what speed does she need to maintain to arrive on time? 9. If a projectile flies north 387 meters in 5.8 seconds, what is its velocity?
10. Calculate the velocity of a mountain climber if that climber is moving northeast at a pace of 1.6 km in 1.4 hours? Give your answer in the SI unit for velocity.