Things to discuss for unit IGet out yourYellow packet

Equation sheetLab manualChapter 2

Assignment from SUB DAY

Page 38 questions 2.3.4.6.8.9

By definition, if an object has a constant velocity, then both the object's speed and its direction ofmotion are constant. Therefore the object CANNOT have a varying speed if its velocity is constant.

When an object moves with constant velocity, its average velocity over any time interval is exactly

equal to its instantaneous velocity at all times

Yes. A car that had the greatest overall velocity throughout the race could falter and be pushed across the finish line while another car with a

nervous driver could finally decide to put the petal to the metal at the end.

The acceleration of both the motorcycle and the bicycle are the same, since the same change in

velocity occurred during the same time interval.If you do a further calculation, you will find that the

distance traveled by the motorcycle during theacceleration is 17 times the distance traveled by the

bicycle.

The velocity of an object can be negative when its acceleration is positive. If we define the positive

direction to be to the right, then an object traveling to the left that is having a reduction in speed will

have a negative velocity with a positive acceleration.If again we define the positive direction to be to the

right, then an object traveling to the right that ishaving a reduction in speed will have a positive velocity

and a negative acceleration.

If north is defined as the positive direction, then an object traveling to the south and increasing in

speed has both a negative velocity and a negative acceleration. Or, if up is defined as the positive

direction, then an object falling due to gravity has both a negative velocity and a negative

acceleration.

Warm Up

The first 20 meters of a 100-meter dash are covered in 3 seconds by a sprinter who starts from rest and accelerates with a constant acceleration. The remaining 80 meters are run with the same velocity the sprinter had after 3 seconds.a. Determine the sprinter's constant acceleration during the first 3 seconds.b. Determine the sprinters velocity after 3 seconds have elapsed.c. Determine the total time needed to run the full 100 meters.d. Sketch a p-t graph that illustrates this problem.

. Determine the velocity v of the object at the end of each 5-second interval. Assume the initial velocity was 2 m/s.

Time (s) Displacement from starting position (m)

6

12

18

21

Plot a p-t graph from this information.