acceleration motion is change of position motion is described by velocity: how fast? which way?...
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ACCELERATIONACCELERATION
Motion is change of positionMotion is described by velocity:
How fast? Which way?Changing motion means:
Speeding up,Slowing down,
Changing direction (turning)
ACCELERATIONACCELERATION• A car is accelerating whenever there is a change
in velocity• Acceleration also applies to changes in direction.
•It is important to distinguish between speed and velocity.
Acceleration is defined as the rate of change in velocity, rather than speed
ACCELERATIONACCELERATION
Acceleration is the rate at which velocity changes:Acceleration is how fast how fast changes or how fast the direction changes
Falling upward: Falling upward: constant accelerationconstant acceleration
Now consider a ball thrown straight up at 30 m/s: What happens on the way up?How fast is the ball moving 1 s, 2 s, 3 s later?Where is the ball when v = 0?How long does the ball take to reach the
highest point?How fast is the ball moving 4 s later?How long does the ball take to reach the
person? How fast is the ball moving when it reaches
the person?
Ball Toss ExperimentBall is in your hands
Ball is in your hands
Ball is in your hands
Ball is in your hands
Ball Toss Experiment
Ball is in your hands
Ball is in your hands
Ball is in Ball is in the airthe air
Ball is in Ball is in the airthe air
Motion with Constant AccelerationMotion with Constant Acceleration
equal
- 4.8 X 2 = 9.6equal
Motion with Constant AccelerationMotion with Constant AccelerationGeneral equations:
y = ½ at2 + vot
v = at + vo
a is constant ( a number)
Free Fall: Constant AccelerationThe acceleration of an object in free fall is about 10 meters per second every secondOr 10 m/s/sThe rock is falling faster and faster:Each second its velocity increases by 10 m/s
Time, seconds
Velocity, m/s
01234
t
Time, seconds
Velocity, m/s
0 01 102 203 304 40
t 10t
Fill out the table:
Graph these values: make a velocity-time graph
Motion with Constant AccelerationMotion with Constant Acceleration
Velocity-Time Graph
On a velocity-versus-time graph, On a velocity-versus-time graph, acceleration = slopeacceleration = slope
Free Fall: Constant AccelerationThe acceleration of an object in free fall is about 10 meters per second every secondOr 10 m/s/sThe rock is falling faster and faster:Each second its velocity increases by 10 m/s
Time, seconds
Velocity, m/s
0 01 102 203 304 40
t 10t
Motion with Constant AccelerationMotion with Constant Acceleration
Position-Time Graph
y = ½ aty = ½ at22
Position, Velocity, and Acceleration
Motion Graphs
Constant Acceleration Graphs
Race Cars