Biomedical Engineering Reference
In-Depth Information
F
obtained by using the calibration curve constructed in activity 1, after the
measurement of
x
i
and calculation of
x
.
2. Determine the readouts of spring scales 1 and 2 as well as the value of angles
Δ
θ
1
and
θ
2
, measured by the protractor.
F
1
¼
θ
1
¼
_____________
_________________
F
2
¼
θ
2
¼
_________________
3. Decompose the forces
F
1
and
F
2
in
x
and
y
components, as shown in Fig.
8.5b
.
F
1
X
¼
_____________
F
1
cos
θ
1
¼
_____________
F
1
Y
¼
F
1
sin
θ
1
¼
_____________
F
2
cos
θ
2
¼
_____________
F
2
Y
¼
F
2
sin
θ
2
¼
_____________
4. Apply the equilibrium conditions in relation to translation and determine the
weight of the suspended object.
W
F
2
X
¼
_____________
5. Measure now directly the weight of the suspended object, using only one spring
scale as already done in Activity 1, and compare it with the value obtained in
4 from the equilibrium condition.
W
¼
¼
_____________
8.4.1 Objectives
• To discuss the concept of the torque of a force
• To establish the equilibrium conditions of a rigid body
• To develop the principle of lever
8.4.2 Activity 3: Torque of a Force
8.4.2.1 Necessary Materials
- A wooden bar or equivalent
- Triangular support or equivalent
- Objects with known mass (30 small marbles with diameter of around 1.2 cm,
for example)
- Devices to hold the masses (plastic cup or equivalent)
- 30 cm ruler or a measuring tape
8.4.2.2 Procedure
1. Establish static equilibrium and measure the masses and distances of the experi-
mental arrangement of Fig.
8.6
, in the following situations:
