# Angular Mechanics (4, 2); Centripetal Force (4, 3); Hooke's Law (4, 4) - HP 48gII Advanced User's Reference Manual

Graphing calculator.

## Angular Mechanics (4, 2)

Equations:
1
- - - I
=
I
K i
=
2
W
=
K f K i
P =
a t
=
r
=
2
Example:
Given: I=1750_lb in^2,
Solution: r=1.1017E–3_ft_ lbf, Ki=0_ft lbf, W=6.9221E–3_ft lbf, Kf=6.9221E–3_ft lbf,
at=8.5069E–4_ft/s^2, Ni=0_rpm, f=11.4868_r/min, t=1.0940_min, Nf=1.8282_rpm, Pavg=1.9174E–7_hp.

### Centripetal Force (4, 3)

Equations:
2
F
=
m
r
Example:
Given: m=1_kg, r=5_cm, N=2000_Hz.
Solution:
=12566.3706_r/s, ar=7895683.5209_m/s, F=7895683.5209_N, v=628.3185_m/s.

### Hooke's Law (4, 4)

The force is that exerted by the spring.
Equations:
F
=
k – x
Example:
Given: k=1725_lbf/in, x=125_in.
Solution: F=-2156.25_lbf, W=-112.3047_ft lbf.
1
2
2
- - - I
i
K f
=
f
2
W
---- -
P a v g
=
t
i
=
2
Ni
N
=360_°, r=3.5_in, =10.5_r/min^2, i=0_r / s.
2
v
v
a r
=
---- -
- - -
=
r
r
1 –
2
W
=
----- - k x
2
W
=
r
f
=
i +
t
f
=
2
Nf
=
2
N
Equation Reference 5-23