PHYSICS 1403, QUIZ 1 Chapters 1 & 2, July 16, 2006

Chapters 1 & 2, July 16, 2006
Partial credit will be LIBERAL, provided that you show your work!
Use back if necessary (please tell me that you have done so!)
Name: ______________________
1. (6 points)
Multiply 5.985 m/s by 6.45  10-6 s, taking into account significant figures.
Express your answer using scientific (power of 10) notation!
If the velocity of an object is zero, does it necessarily mean that the acceleration is
zero? Give a brief example to justify your answer!
3. (18 points)
At time t = 0, an object is dropped vertically downward with zero initial velocity
from a height of 80 m above the ground. (Hints: It’s not required, but it might be convenient
to take DOWN as positive to solve this! Be cautious when thinking of the height above the ground.
The height and the distance from the starting point are related, but they obviously aren’t the same!)
a. Calculate the time it takes to hit the ground.
b. Calculate is its velocity just before it hits the ground.
c. Calculate its velocity when it has reached a height of 40 m above the ground.