# Acceleration Define acceleration How about scientifically?

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Acceleration Define acceleration How about scientifically?
Rate of change of velocity What is a rate? What is velocity?

Acceleration of Selected Events (Smallest to Largest)
a (m/s2) event  5 × 10−14 smallest acceleration in a scientific experiment 2 × 10−10 galactic acceleration at the sun 0.5 elevator, hydraulic 1 elevator, cable 1.6 free fall acceleration on the moon 8.8 International Space Station 3.7 free fall acceleration on Mars 9.8 free fall acceleration on Earth 10–40 manned rocket at launch 20 space shuttle, peak 24.8 free fall acceleration on Jupiter 20–50 roller coaster 80 limit of sustained human tolerance 0–150 human training centrifuge 100–200 ejection seat 270 free fall acceleration on the sun 600 airbags automatically deploy 104–106 medical centrifuge 106 bullet in the barrel of a gun

Automotive Acceleration (g)
event typical car sports car F-1 race car large truck starting 0.3–0.5 0.5–0.9 1.7 < 0.2 braking 0.8–1.0 1.0–1.3 2 ~ 0.6 cornering 0.7–0.9 0.9–1.0 3 ??

Acceleration and the Human Body
a (g) event 2.9 sneeze 3.5 cough 3.6 crowd jostle 4.1 slap on back 8.1 hop off step 10.1 plop down in chair 60 chest acceleration during car crash at 48 km/h with airbag, design limit 70–100 crash that killed Diana, Princess of Wales, 1997 150–200 head acceleration limit during bicycle crash with helmet

Types of Acceleration What are three ways that an object can accelerate? What does velocity look like during these times?

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?

Acceleration… How do we calculate it? OR
Think of the definition It is a rate of change of a velocity OR What should the standard SI units look like? What are the units for velocity? What are the units of time?

Example A 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?

Solution A cart goes from rest to 10 m/s away from you in 2 s. What is the cart’s acceleration? a=? vi= 0 m/s vf=10 m/s away t= 2 s

Solution 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? a=? vi= 3 m/s west vf=0 m/s t= 2 s

Your turn A 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.

Solution A 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/s vf=108 km/h north= 30m/s N t= 10 s First we need to convert km/h to m/s…

Solution 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. a=? t= 1/30 s vf=50 m/s towards the pitcher or vi= 40 m/s towards the batter or vf=-50 m/s towards the batter vi= -40 m/s towards the pitcher Our 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!

Two Dimension Motion Circular motion Centripetal acceleration
We looked at this before Centripetal acceleration What do you think this is? Hint: Think about the acceleration of the lady bug.

Projectile Motion What is a projectile?
What path does a projectile travel? What are the two components of projectile motion? Vh= 2.0 m/s Vv= 0.0 m/s Vv= 0.5 m/s Vv= 1.0 m/s

Throwing vs. Dropping Will 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