THIS MINI-LESSON WILL COVER: What is the difference between scalars and vector quantities? What is the difference between distance and displacement ? How can vectors be added or subtracted to show final direction?
What are scalars? Scalars are quantities that only have magnitude (size). Ex: Temperature
What are Vectors? Vectors are quantities that have both magnitude (size) and direction. Ex: Force – you push something with a certain amount of force (magnitude) in a particular direction. Vectors can be represented by an arrow. The length of the arrow represents the magnitude and the arrow points in the direction.
Practice: Work with your partners to sort the following quantities into scalars and vectors. Distance Displacement Velocity Speed Energy Acceleration Time Number of fish in a pond Force Temperature Momentum Mass
Answers SCALARS Distance Speed Energy Mass Time Number of fish in pond Temperature VECTORS Displacement Velocity Acceleration Momentum Force
Day 2: Distance vs. Displacement Distance: - The actual path of an object. Displacement – the change in position. It gives the straight line distance from where you start to where you end. An x is usually used the symbol for displacement. displacement = final position – initial position x = x f - x i
33 Solve the problem 1) The straight line distance from a student’s house to school is 2 kilometers. If the student walks 2 kilometers to his friends house first and then 2 kilometers to school, what was the total distance traveled? What was his displacement? Answer: distance = 4 km displacement = 2 km North (Don’t forget direction) 2 km
Solve the problem 2) The space shuttle takes off from Florida and circles the Earth 10 times before landing back in Florida. If one orbit is 41 thousand kilometers, what was the shuttles distance travelled? What was its displacement? Answer: distance = 410,000 km Displacement = 0 km
Day 3: Vector Addition Vectors are helpful because they can be added to find both final magnitude and final direction. Ex. A person walks west for 10 km and stops. After an hour they walk another 15 km west. What was his final displacement? To solve, use vector addition. 10 km, west15 km, west x = 10 km + 15 km = 25 km west
Vector addition cont… Ex. 2) A person walks 10 km west, turns around, and then walks 15 km east. What is her displacement? Try to solve on your own. 10 km, west 15 km, east X = 15 km – 10 km = 5 km, east
Vector addition cont. A person walks 100 m south and then 100 m west. What was his final direction? Try to solve on your own. Answer: Southwest ***Quiz: Tomorrow