Force Between Two Objects
The following equation can be used to calculate the gravitational force
between two masses or the electrical force between two charged
objects:
F=KxAxB+RA2
where
A
=
the mass (in kilograms) or electrical charge (in cou-
lombs) of object A.
B=
the mass (in kilograms) or electrical charge (in cou-
lombs) of object B.
the force (in newtons).
F=
K=
a constant. K
=
6.67
X
10-
11
N-m
2
jkg
2
(gravitation)
or K
=
8.98756
X
10
9
C2 jN-m
2 .
R=
the distance between the objects (in meters).
Example: Gravitational Force. Calculate the gravitational force be-
tween the earth and the sun. The earth's mass is 5.983 x 10
24
kg; the
sun's mass is 1.938 x 10
30
kg. The sun is 9.3 x 10
7
miles from earth.
Keys:
Display:
I
EVAL
I
K?value
5.983
.m
24
I
INPUT
I
B?value
1.938.m 30
I
INPUT
I
R?value
9.3.m 7052800
120
R?5.8925E12
98
7: The Equation Library
Description:
Prompts for K.
Stores K, prompts for
mass of object A
(earth).
Stores
A,
prompts for
mass of object B (sun).
Stores B, prompts for
R.
Converts miles to
inches.