General Mechanics Apparatus Flashcards
Data logger + suitable sensor + PC or notebook
Common Sensors: force(newton meter), temperature, time, voltage, current, magnetic flux, density, pressure, photo-gate for time measurement, motion sensor. Use block diagram to illustrate connection.
Use these only when you are desperate.
*Must state type of sensor
Slotted masses + hanger
Used to measure an applied force.
The load (vertical force), can be increased or decreased by a small and constant amount.
A small amount of sand can be used f smaller mass variation is required.
Plumb-line (consist of a bob tied to a string).
Used to ensure vertical alignment (the c.g. measurement thing)
Pulley
To change the direction of a force along string.
Vernier callipers
External and internal jaws to measure external and internal diameter.
The protruded tail can be used to measure the depth of a hole which cannot be reached by a ruler.
Video camera with freeze frame facility
Useful when measuring a relatively fast changing variable, e.g. measure the the bounce height of a basketball, measured against the ruler that is stuck on a wall behind it.
Can play back the video and pause at necessary point to take a reading.
Light gates = electronic timer
To measure time interval of moving object.
Two gates are often used. The first gate starts the time when the object blocks the path of light and the second gate stops the time when the object blocks the light path.
Useful only when the object blocks the light path Eg. Motion along guided track.
Ticker-tape timer
Used for measuring speed and then calculating the acceleration over short distances.
Air track and accessories
To perform simple mechanical interactions like collisions on a guided track with negligible friction.
Pressure gauge/manometer/barometer
To measure gas/air pressure
Vacuum pump
A motorised device to extract air from a container.
Pump
Pump gas into a container
Constant flow tank (also called a Header tank)
Water flows out of the tank at constant rate because the “pressure head” is always maintained at a constant value.
Travelling microscope
The objective lens and eye piece of the microscope are mounted on a movable track with a linear scale. This device is useful for measuring the dimensions of small objects where micrometer scre gauge cannot be used.
Eg the internal diameter of a capillary tube, the width of a narrow slit.
