Science Starter Take out last night’s homework We are going to go over it together.
-
Upload
martha-collins -
Category
Documents
-
view
218 -
download
3
Transcript of Science Starter Take out last night’s homework We are going to go over it together.
![Page 1: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/1.jpg)
![Page 2: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/2.jpg)
Science Starter
•Take out last night’s homework
•We are going to go over it together
![Page 3: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/3.jpg)
Problem 1
• John drove South 120 km at 60 km/h and then East 150 km at 50 km/h. a) Draw and label the vectors
•b) Determine the average speed for the whole journey? c) Determine the magnitude of the average velocity for the whole journey?
![Page 4: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/4.jpg)
Problem 2
• If I can walk at an average speed of 5 km/h, how many miles I can walk in two hours?
![Page 5: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/5.jpg)
Problem 3
A man walked from point A to F following the route in the grid below in 3250 seconds. Determine
A man walked from point A to F following the route in the grid below in 3250 seconds. Determine
a) the average speed, in m/s, for the whole journey. b) the magnitude of the displacement. c) the magnitude of the average velocity, in m/s, for the whole journey.
a) the average speed, in m/s, for the whole journey. b) the magnitude of the displacement. c) the magnitude of the average velocity, in m/s, for the whole journey.
![Page 6: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/6.jpg)
Problem 4
•A runner makes one lap around a 200 m track in a time of 25.0 s. What was the runner's average speed?
![Page 7: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/7.jpg)
Problem 5
•Light and radio waves travel through a vacuum in a straight line at a speed of very nearly 3.00 108 m/s. How far is light year (the distance light travels in a year)?
![Page 8: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/8.jpg)
Problem 6
•A motorist travels 406 km during a 7.0 hr period. What was the average speed in km/hr and m/s?
![Page 9: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/9.jpg)
Problem 7
•A bullet is shot from a rifle with a speed of 720 m/s. What time is required for the bullet to strike a target 3240 m away?
![Page 10: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/10.jpg)
Agenda
•Science Starter• Intro to Acceleration•Lab
![Page 11: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/11.jpg)
Objective
•SWBAT define and calculate acceleration
![Page 12: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/12.jpg)
Change in Velocity
• Each time you take a step you are changing the velocity of your body.
• You are probably most familiar with the velocity changes of a moving bus or car.
• The rate at which velocity (speed or direction) changes occur is called acceleration.
![Page 13: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/13.jpg)
Vocab
•Acceleration - The acceleration of an object is a measure of how quickly its velocity changes.
![Page 14: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/14.jpg)
Formulas
Acceleration= final velocity- starting velocity
time
Change in velocity = final – starting
velocity velocity Acceleration= change in velocity
time
![Page 15: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/15.jpg)
PositivePositive acceleration acceleration
Negative Negative accelerationacceleration
![Page 16: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/16.jpg)
A train accelerates in a straight line from rest. As it does, its velocity increases.
The brakes on this motorcycle are causing it to slow down. This is negative acceleration or deceleration.
What is acceleration?
![Page 17: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/17.jpg)
The acceleration of an object can be calculated using this equation:
change in speed
time takenacceleration =
Acceleration is measured in metres per second per second (m/s2).
Change in speed is measured in metres per second (m/s).
Time taken is measured in seconds (s).
How is acceleration calculated?
![Page 18: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/18.jpg)
A racing car accelerates from rest to a speed of 60 m/s in a time of 4 seconds. What is the acceleration of the car?
= 15 m/s2
change in speed
time takenacceleration =
= 60
4
Acceleration problem
![Page 19: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/19.jpg)
Using a formula triangle
A formula triangle helps you to rearrange a formula. The formula triangle for acceleration (a), speed (s) and time (t) is shown below.
x
Cover the quantity that you are trying to work out.
So to find acceleration (a), cover up a…
…which gives the formula…
a =s
t
![Page 20: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/20.jpg)
A hungry cheetah spots a gazelle and decides to chase it. The cheetah accelerates at 10
m/s2 from rest until it reaches 20 m/s. How long did this take?
acceleration = change in speedtime taken
= 2010
= 2 s
Acceleration problem
time taken = change in speedacceleration
![Page 21: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/21.jpg)
- A constant acceleration
produces a straight line or linear slope
(rise/run).
- The slope of a non-linear velocity-time graph (rise/run) will predict an objects
instantaneous acceleration.
a = v/t
![Page 22: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/22.jpg)
Acceleration =Velocity(final) - Velocity(original)
time
A car traveling at 60 mph accelerates to90 mph in 3 seconds. What is thecar’s acceleration?
=90 mph - 60 mph
3 seconds
=30 mph
3 seconds
= 10 mph/second
![Page 23: Science Starter Take out last night’s homework We are going to go over it together.](https://reader035.fdocuments.in/reader035/viewer/2022081515/56649f485503460f94c6a702/html5/thumbnails/23.jpg)
Acceleration =Velocity(final) - Velocity(original)
time
A car traveling at 60 mph slams on the breaks to avoid hitting a deer. The car comes to a safe stop 6 seconds after applying the breaks. What is thecar’s acceleration?
=0 mph - 60 mph
6 seconds
=- 60 mph
6 seconds
= - 10 miles per hour per second