2.5 Free Fall: How Fast
Free falling objects are only affected by gravity.
Some students to determine the acceleration due to gravity collected the following data.
Time (s)
0
1
2
3
4
5
Velocity (m/s)
0
10
20
30
40
50
Velocity (m/s)
Graph the students data
Time (s)
Determine the slope of the resultant velocity time graph.
What is the acceleration due to gravity (g) (Hint: Slope of the line)?
The velocity of a free falling object can be calculated using the following equation
v  gt
Identify the variables in the above equation in the table below
Variable
v
g
t
Description
How Far?
The area under the velocity time graph is distance traveled. Some physics students at
Park View High School recorded the following velocity time date in an experiment using
a radio-controlled car.
Velocity Time Graph
A
B
C
D
Velocity (m/s)
100
90
80
70
60
50
40
30
20
10
0
0
2
4
6
8
10
12
14
16
18
20
22
time (s)
24
25
Help the students determine the distance traveled by the radio-controlled car.
Position
Distance
A–B
B–C
C –D
A–D
Distance traveled can also be calculated using the following equation
d
1 2
at
2
Identify the variables in the above equation in the table below.
Variable
d
a
t
Description
The velocity of an object can be determine using the following equation
v  at
Variable
v
a
t
Description
Chapter 2 Equations
Equation
v  at
v  gt
1
d  at 2
2
When do I use this equation
Determine the velocity of an object given acceleration and time
Determine the velocity of an object in free fall after some time
Determine the distance traveled by an object given acceleration and time