Transcript Powerpoint

Physics 151 Week 4 Day 2
Topics
– Motion Graphs
– Area under a curve (velocity to position)
– Constant acceleration equations
Motion Graph Demonstrations
Slide 2-4
Velocity to Position: Example 1
Find the position at times t = 1, 2, 3, 4, and 5 seconds.
Assume x (t = 0 sec) = 0 m.
What is the displacement of the object between t = 1s and t =
3 s?
Slide 2-34
Velocity to Position: Example 2
• Describe in words the motion of the object whose velocity
graph is given below. What is happening at t = 2 s?
• Draw a motion diagram of the objects motion.
• Draw the corresponding position vs. time graph.
Assume initial position is 5 m.
• Give an example of an object that would move this way
Slide 2-34
Checking Understanding
An arrow is launched vertically upward. It moves straight up to a
maximum height, then falls to the ground. The trajectory of the
arrow is noted. Which graph best represents the vertical velocity of
the arrow as a function of time? Ignore air resistance; the only force
acting is gravity.
Slide 2-28
Answer
An arrow is launched vertically upward. It moves straight up to a
maximum height, then falls to the ground. The trajectory of the
arrow is noted. Which graph best represents the vertical velocity of
the arrow as a function of time? Ignore air resistance; the only force
acting is gravity.
Slide 2-29
Start your engine (velocity and acceleration)
On the on ramp to Interstate 25 a car accelerates at 7 m/s2
from rest.
What is the car's velocity at 1 second after it starts from
rest?
2 seconds?
3 seconds?
4 seconds?
Express your reasoning in words.
Slide 2-34