Newton’s 2nd law of motion
Chapter 3
Acceleration
•
A change in velocity
•
*a change in speed, direction, or both
• The
rate of change in velocity:
Speed vs. time graphs
•
the slope of the line shows acceleration
- Speed is constant
- No acceleration
- Speed is increasing at a constant rate
- Constant, positive acceleration
- Speed is decreasing at a constant rate
- Constant, negative acceleration
- Speed is gradually increasing
- Increasing acceleration
- NOT constant
- Speed is gradually decreasing
- Increasing negative acceleration
- NOT constant
•A
ball rolls down a ramp for 15s. If the initial
velocity of the ball was 0.8 m/s and the final
velocity was 7 m/s, what was the acceleration
of the ball?
•A
rocket traveling at 400 m/s fires its booster
rockets until the craft reaches 550 m/s. If the
boosters fire for 30s, what was the
acceleration of the rocket?
• After
applying its breaks, a car accelerates at
a rate of -15m/s/s. If the car was traveling at a
rate of 25 m/s, how long will it take the car to
stop?