# car

```Lab#5
Increasing and Decreasing Speed
JianLin, Wang
Period 5
Apparatus: Dynamics track;cart;books (to elevate track); motion detector; Logger pro
software or LabQuest
1.
Procedure: During the experiment there is 6 station, at each station we need observe
the motion of cart, and we draw the three graph wich is position-time Velocity-time
Acceleration-time graphs of the carts motion.Then we turn on the motion detector
compare our predictions to the resulting motion graphs.
1. Increasing speed in the positive direction
A.The cart would be accelerate because the track is tiled so it make the speed of car increase
moving downward
B.
C. The velocity is positive
d.The acceleration is positive
E.Predict the graph describing the motion.
Position time graph: The graph is a quadratic line and curved with positive slope.
Velocity time graph:The graph is a linear line with positive slope.
Acceleration time graph: The graph is a linear line with positive slope.
F.Record the graphs as displayed by the motion detector.
G. The slope of the position time graph is increasing and positive and represent velocity
H.The slope of the the velocity time graph is increase and positive and represent the
acceleration is constant.
2.Decreasing speed in the positive direction
A. When we push the car the car is start on at high speed, then the car start slowing down,
because the track is tile and the car has to go the upward,so the speed decreasing
B.
C.The velocity is negative
D. The acceleration is negative
E.Predict the graphs describing the motion
Position time graph: The group is a quadratic line with down curved and the slope is negative
Velocity time graph: The group is linear line with negative slope
Acceleration time graph: The group is horizontal line.
F.Record the graphs as displayed by the motion detector
G.The slope of the position time graph is decreasing and negative and represent velocity is
negative
H.The slope of the velocity time graph is decreasing and negative it represent the acceleration
is negative.
3.
Increasing speed in the negative direction
A. The speed of cart would increasing, because the track is tilt the car will move to the motion
detector.
B
C.The velocity is negative
D.The acceleration is negative
E. Predict the graph describing the motion
Position time graph: Quadratic line with negative slope and curved down
Velocity time graph: Linear line with negative slope
Acceleration time graph: Negative horizontal line
F.Record the graph as displayed by the motion detector
G.The slope of the position time graph is increase and negative represent velocity
H.The slope of the velocity time graph is constant and negative is represents there is no
acceleration.
4.Decreasing speed in the negative direction
A. The cart would moving fast at the starting point when we push the car , then it would start
slows down . Then, it would stop at its highest point.
B.
C. The velocity is negative
D. The acceleration is positive
E. Predict the graphs describing the motion
Position time graph: Quadratic line with negative slope and curved down
Velocity time graph:Linear negative line with positive slope
F.Record the graphs as displayed by the motion detector
G. The slope of the position time graph is decreasing and negative and represents the velocity is
negative.
H. The slope of the velocity time group is constant and positive it represents the acceleration is
not change.
5.
Up and down the ramp
A.The cart would moving upward when we push , then it would slows down to the zero . Then it
would change the direction, which moving back in a increasing of speed.
B.
C.The velocity is both positive and negative the direction change when the car up to the
maximum.
D. The acceleration is negative and the direction is not change.
F.Record the graphs as displayed by the motion detector
G. The slope move up with positive slope,but it decreasing. after it move to the highest point ,it
start drop in a negative slope.
H. It has the average of negative slope.
6.Up
and down the ramp
a. A.The cart would moving at high speed when we push it , then it would slowing down at
highest point, and moving back in a increasing speed.
b.
c. The velocity are both positive and negative velocity. And it change direction from negative
to positive.
d. Positive acceleration and no direction change
e. Predict the graphs describing the motion
Position time graph :Quadratic line that in a curve
Velocity time graph : Linear line start with negative, then went into positive with
positive slope.
Acceleration :positive horizontal line.
F .Record the graphs as displayed by the motion detector
G. the graph start at the positive position then moving down and move on it minimum point,
and it start moving up with a increasing of velocity.
h. Velocity had an average of positive slope.
```