Motion graphs | ||
#1 | A steeper line on a postion vs. time graphs indicates what about the speed? |
Moving faster |
#2 | What does a flat line on a speed vs. time graph represent in terms of acceleration?
|
zero acceleration |
#3 | sketch a postion vs. time, speed vs. time, and acceleration vs. time graph for an object that is slowing down at a constant rate in the + direction. |
See board |
#4 | sketch a position vs. time graph for the following scenario: A man walks forward at a constant rate, then he starts running at a constant rate, then he slows gradually to a stop and stays stopped. |
See board |
#5 | sketch the position vs. time graph, velocity vs. time graph, and acceleration vs. time graph for a skydiver jumping out of an airplane until they reach the ground. |
see board |
Friction | ||
#1 | What Greek letter is used to signifiy the coefficient of friction? |
mu |
#2 | To find the coefficient of kinetic friction by what must you divide the frictional force needed to keep an object moving at a constant rate? (Be more specfic than "weight") |
Normal force |
#3 | If you were wanting to see how far you could slide along a sidewalk when it was rainy, would you want a shoe with a mu of .5 or .2? |
.2 |
#4 | What is the SI unit for the coefficient of friction? |
There is no unit
Newtons/Newtons cancel out |
#5 | A box slides down a ramp. A 10-N force of gravity is pulling the box down the ramp while a 2-N force of friction acts to stop the box. What is the net force accelerating the box down the ramp? |
8 newtons |
Acceleration | ||
#1 | A car drives at constant speed around a corner. Is it accelerating? |
Yes, the velocity is changing because the direction is changing and thus there is a net force acting on the car and thus there is acceleration. |
#2 | The constant slope of a velocity (m/sec) vs. time (sec) graph is -1.3 . What is the acceleration of the object that is being graphed? |
-1.3 m/sec2 |
#3 | An object is moving forward but has negative acceleration. Describe this motion. |
slowing down |
#4 | The acceleration due to gravity is: |
e |
#5 | A sports car reaches a speed of 25 m/s in 5 seconds after starting from rest. If its acceleration stays the same, what will the speed of the car be at 10 seconds? |
b 50 m/sec |
Force | ||
#1 | What is the powerful energy field used by the Jedi in Star Wars called? |
The Force |
#2 | The moon is 1/6th as massive as the earth. What would the mass of a 60 kg person be on the moon? |
60 kg |
#3 | The g force on Mars is roughly 2/5 of the earth's. How would the weight of a 100 pound person on earth compare to their weight on Mars? |
100 pounds on earth is about 40 pounds on Mars |
#4 | An object weighs 600. newtons on earth. What is its mass, in kg? |
61.2 kg
w= m x g
m= w/g
600/9.8 |
#5 | Two men are having a tug-of-war. One individual pulls East with a force of 1000 newtons, and the other pulls to the West with a force of 1,200 newtons. Describe the net force and direction with a vector and state the tension on the rope. |
200 newtons west
Tension on rope = 1000 newtons
System will be accelerating to the west |
Potpourri | ||
#1 | Which of the following is a projectile: A ball thrown into the air An airplane A ball rolling across a field A stapler sliding across a desk |
Ball thrown into the air |
#2 | Ta on the data collector reads .0071 s after your energy car passes photogate A. What is the speed of the car at photogate in cm/sec? |
140 cm/sec
1.00/.0071 = 140.85 |
#3 | The force of gravity acting on one kilogram on the earth is |
9.8 newtons |
#4 | Which of the following is not an OHS value: Positive Attitude Respect Compassion Integrity Whining |
Whining |
#5 | What must be true of an object that has no net force acting on it? Answer with regards to the velocity of the object. |
moving at constant velocity |
Final Question | |
Make a rough sketch of a force vector diagram to determine in which direction the following object would travel. 10 N east 30 N North 15 N Northwest 40 N West
Answer with NE, NW, SE, or SW |
NW |