Acceleration March 2, 2010. Objectives 1. Define acceleration and deceleration 2. Describe the...
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Transcript of Acceleration March 2, 2010. Objectives 1. Define acceleration and deceleration 2. Describe the...
Objectives1. Define acceleration and deceleration
2. Describe the relationship between velocity and acceleration
3. Calculate acceleration
Speed vs Velocity?
Speed – how fast an object is changing its position
Velocity – an object’s speed and direction
Velocities can be combined.
Rowing downstream at 16 km/h southeast on a river which is moving 10 km/h southeast
results in a total velocity of 26 km/h southeast.
Acceleration unitskm / h /h or km / h2
m/s/s m / s2
km / h /s
kilometers per hour per hour
meters per second per second
kilometers per hour per second
Example problem
A roller coaster’s speed at the top of a hill is 10 m/s. Two seconds later, it reaches the bottom of the hill with a speed of 26 m/s. What is the acceleration of the roller coaster?
Vi
Vf
t
A = V T
Final velocity = 26 m/s Initial velocity = 10 m/s Time = 2 s
A = 26 m/s – 10 m/s = 16 m/s = 8 m/s/s
2s 2s
Example Problem At the end of a race,
a bicycle is decelerated from a velocity of 12 m/s to a rest position in 30 seconds. What is the deceleration of this bicycle?
Vi
Vf t
A = V T
Final velocity = 0 m/s Initial velocity = 12 m/s Time = 30 s
A = 0 m/s – 12 m/s = -12 m/s = -0.4 m/s/s
30s 30s
If a rocket in space is moving at a constant velocity of 9.8 m/s and then uses its propulsion system to accelerate to 12.0 m/s during a 3.0 minute burn, what would be the acceleration of the rocket?
A = Vf – Vi
t
If a rocket in space is moving at a constant velocity of 9.8 m/s and then uses its propulsion system to accelerate to 12.0 m/s during a 3.0 minute burn, what would be the acceleration of the rocket?
A = Vf – 9.8 m/s
t
If a rocket in space is moving at a constant velocity of 9.8 m/s and then uses its propulsion system to accelerate to 12.0 m/s during a 3.0 minute burn, what would be the acceleration of the rocket?
A = 12.0 m/s – 9.8 m/s
t