Presentation on theme: "Acceleration Define acceleration How about scientifically?"— Presentation transcript:
1 Acceleration Define acceleration How about scientifically? Rate of change of velocityWhat is a rate?What is velocity?
2 Acceleration of Selected Events (Smallest to Largest) a (m/s2)event 5 × 10−14smallest acceleration in a scientific experiment2 × 10−10galactic acceleration at the sun0.5elevator, hydraulic1elevator, cable1.6free fall acceleration on the moon8.8International Space Station3.7free fall acceleration on Mars9.8free fall acceleration on Earth10–40manned rocket at launch20space shuttle, peak24.8free fall acceleration on Jupiter20–50roller coaster80limit of sustained human tolerance0–150human training centrifuge100–200ejection seat270free fall acceleration on the sun600airbags automatically deploy104–106medical centrifuge106bullet in the barrel of a gun
4 Acceleration and the Human Body a (g)event2.9sneeze3.5cough3.6crowd jostle4.1slap on back8.1hop off step10.1plop down in chair60chest acceleration during car crash at 48 km/h with airbag, design limit70–100crash that killed Diana, Princess of Wales, 1997150–200head acceleration limit during bicycle crash with helmet
5 Types of AccelerationWhat are three ways that an object can accelerate?What does velocity look like during these times?
6 What happened from 0-0. 5 min. 5- 1. 5 min. 1. 5- 2. 0 min. 2. 0- 3 What happened from min? min? min? min? min? min? min? min? min?
7 Acceleration… How do we calculate it? OR Think of the definitionIt is a rate of change of a velocityORWhat should the standard SI units look like?What are the units for velocity?What are the units of time?
8 ExampleA cart goes from rest to 10 m/s away from you in 2 s. What is the cart’s acceleration?A skateboarder has an initial velocity of 3 m/s west and comes to a stop in 2 s. What is the skateboarder’s acceleration?
9 SolutionA cart goes from rest to 10 m/s away from you in 2 s. What is the cart’s acceleration?a=? vi= 0 m/svf=10 m/s away t= 2 s
10 SolutionA skateboarder has an initial velocity of 3 m/s west and comes to a stop in 2 s. What is the skateboarder’s acceleration?a=? vi= 3 m/s westvf=0 m/s t= 2 s
11 Your turnA car goes from rest to a velocity of 108 km/h north in 10 s. What is the car’s acceleration in m/s?A baseball is pitched at 40 m/s (90 mph) in a Major League game. The batter hits the ball on a line drive straight toward the pitcher at 50 m/s (112 mph). Determine the acceleration of the ball if it was in contact with the bat for 1/30 s.
12 SolutionA car goes from rest to a velocity of 108 km/h north in 10 s. What is the car’s acceleration in m/s?a=? vi= 0 m/svf=108 km/h north= 30m/s N t= 10 sFirst we need to convert km/h to m/s…
13 SolutionA baseball is pitched at 40 m/s (90 mph) in a Major League game. The batter hits the ball on a line drive straight toward the pitcher at 50 m/s (112 mph). Determine the acceleration of the ball if it was in contact with the bat for 1/30 s.a=? t= 1/30 svf=50 m/s towards the pitcher or vi= 40 m/s towards the batter orvf=-50 m/s towards the batter vi= -40 m/s towards the pitcherOur issue is that we can’t calculate the acceleration unless the velocities are in like terms. We can flip either velocity, when we do this we must change the sign (positive to negative or vice versa). Once we do that we can solve as usual!
14 Two Dimension Motion Circular motion Centripetal acceleration We looked at this beforeCentripetal accelerationWhat do you think this is?Hint: Think about the acceleration of the lady bug.
15 Projectile Motion What is a projectile? What path does a projectile travel?What are the two components of projectile motion?Vh= 2.0 m/sVv= 0.0 m/sVv= 0.5 m/sVv= 1.0 m/s
16 Throwing vs. DroppingWill a ball that is thrown as hard as you can throw it and an identical ball dropped (zero added force) straight down land at the same time or different times? Why?Video
17 Amusement Parks http://www.youtube.com/watch?v=0WpNSImh6Z8 How do amusement park rides create “thrills”? What do you feel when you are on roller coasters or waterslides?