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Warm-up: on your own paper. 320.4 hL = ______ cL 150 mL = _______ kL 115.0 cL = ________L 50 L = ______ dL 1L = ______ hL. If you listen to this song, it will tell you the mass of a grain of rice and a text book. The right answers get you candy. (you have to have both!!).
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Warm-up: on your own paper 320.4 hL = ______cL 150 mL = _______ kL 115.0 cL = ________L 50 L = ______dL 1L = ______hL
If you listen to this song, it will tell you the mass of a grain of rice and a text book. The right answers get you candy. (you have to have both!!)
4. What is the speed of a horse in meters per second that runs a distance of 1.2 miles in 2.4 minutes? Step 1: conversion factor for miles to meters : 1km / 0.621miles Step 2: conversion factor for minutes to seconds 1 minute / 60 seconds
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 2,541 meters through the park and the time it took to cover that distance was 43.6 minutes, what was the speed of the Jogger? Step 1: meters is good, leave it alone. Step 2: conversion factor for minutes is 1 min / 60 sec.
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 ? Step 1: for the ball, okay to solve as is… Step 2: for the fish, convert minutes to seconds ( use conversion factor I gave you on # 6)
If Seneca decides to walk across town to a store that is .95 km away and she has only 25 minutes to get there, what speed does she need to maintain to arrive on time? Step 1: covert kilometers to meters Step2: convert minutes to seconds
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 SI unit for velocity. Step 1 : convert km to meters Step 2: convert hours to seconds
Speed = distance/ time • constant speed • instantaneous speed • average speed • symbol for speed is v unit is m/s • symbol for distance is d unit is m • Symbol for time is t unit is s
Velocity describes speed and direction of a moving object. Velocity can be represented with arrows. The length of the arrows are proportional to the magnitude and the arrowheads indicate the direction. The arrows are called vectors.
Acceleration: Changing speed Changing direction acceleration = change of velocity time a = vf – vi t
Lab: speed of a tennis ball ( 3 trials) • Make a chart • Measure 3 distances : .5Dm, .6 Dm, .07hm • Document what distance you are going with. • Time how long it takes to roll the ball that • distance. Document the time. • Convert speed to meters per second. • As a whole class, I am going to teach you how • To convert this time to km/hr.
Deceleration means to slow down. Negative acceleration is an acceleration in the direction that has been designated as negative. When an object accelerates in the same direction as its velocity, it speeds up. When the acceleration is in the opposite direction as its velocity, the object will slow down.
What distance will a car cover accelerating from 12 m/s to 26 m/s in 14s? What are your givens? What is your unknown? What is your formula? What are the symbols What are the units?
Warm-up: 1. What is the volume of a Jenga block? (L x W x H) 2. Convert your number to Decameters.
Vocabulary: Momentum Inertia Mass Velocity Skills: Solve problems using the formula Symbols and units involved Perform a lab
Copy: • Momentum: "mass in motion” • Equation: p = m x v • Unit: kg*m/s
Momentum • All objects have mass; so if an object is moving, then it has momentum - it has its mass in motion. • The amount of momentum which an object has is dependent upon two variables: • how much matter is moving? • how fast the matter is moving?
Momentum • Momentum is a vector quantity.
Momentum Consider a Mack truck and a roller skate moving down the street at the same speed. The considerably greater mass of the Mack truck gives it a considerably greater momentum. If the Mack truck were at rest, which would have the greater momentum? If an object is at rest, the momentum of that object is “0” because there is nomass in motion.
Lab: copy on your note sheet A bouncy ball has 5g of mass A tennis ball has 20g of mass Find the speed (v = d/t) of the bouncy ball when you roll it 7 meters. If you do not have good Control of your ball, I will take it from you and serve you with a detention slip. 4. Find the speed of the tennis ball when you roll it 7 meters. Same goes as above.
Momentum Questions 1. Determine the momentum of a ... a.) 60 kg halfback moving eastward at 9 m/s. b.) 1000 kg car moving northward at 20 m/s. c.) 40 kg man moving southward at 2 m/s. p = 540 kg*m/s, east p = 20,000 kg*m/s, north p = 80 kg*m/s, south
Momentum Questions 2. A car possesses 20,000 units of momentum. What would be the car's new momentum if ... a.) its velocity were doubled b.) its mass were doubled c.) both its velocity and mass were doubled p = 40,000 units p = 40,000 units p = 80,000 units
If the boulder and the boyhave the same momentum,will the boulder crush the boy? Hint: think about the momentum formula! p = mv