Browse Definitions:
Definition

pascal (unit of pressure or stress)

The pascal (pronounced pass-KAL and abbreviated Pa) is the unit of pressure or stress in the International System of Units (SI). It is named after the scientist Blaise Pascal. One pascal is equivalent to one newton (1 N) of force applied over an area of one meter squared (1 m2). That is, 1 Pa = 1 N · m-2. Reduced to base units in SI, one pascal is one kilogram per meter per second squared; that is, 1 Pa = 1 kg · m-1 · s-2.

If a pressure p in pascals exists on an object or region whose surface area is A meters squared, then the force F, in newtons, required to produce p is given by the following formula:

F = pA

Suppose a small rocket engine produces 100,000 (105) Pa of pressure, and the nozzle has a cross-sectional area of 1/10,000 of a square meter (10-4 m2). Then the force F, in newtons, produced by the engine is:

F = pA = 105 x 10-4 = 10

Imagine that this engine is used in a propellant pack for a space walker whose mass is 50 kg. How fast will the person accelerate relative to nearby objects in the weightless environment of earth orbit? The answer is found by the familiar formula stating that force is equal to mass times acceleration (F = ma). This can be manipulated to obtain:

a = F / m

where a is the acceleration in meters per second squared, F is the force in newtons, and m is the mass in kilograms. Plugging in the known numbers:

a = 10 / 50 = 0.20

The acceleration is 0.20 m/s2. If the rocket engine is fired continuously by a space walker who is stationary relative to another object nearby, then after one second she will be moving at a speed of 0.20 m/s with respect to that object; after two seconds she will be traveling at 0.40 m/s; after three seconds she will be moving at 0.60 m/s; and so on.

Also see kilogram, meter, meter per second, meter per second squared, newton, second, SI, and Table of Physical Units.

This was last updated in September 2005

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

SearchSecurity

  • copyright

    Copyright is a legal term describing ownership of control of the rights to the use and distribution of certain works of creative ...

  • keylogger (keystroke logger or system monitor)

    A keylogger, sometimes called a keystroke logger or system monitor, is a type of surveillance technology used to monitor and ...

  • password

    A password is an unspaced sequence of characters used to determine that a computer user requesting access to a computer system is...

SearchHealthIT

SearchDisasterRecovery

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

  • mass notification system (MNS)

    A mass notification system is a platform that sends one-way messages to inform employees and the public of an emergency.

SearchStorage

  • CompactFlash card (CF card)

    A CompactFlash card (CF card) is a memory card format developed by SanDisk in 1994 that uses flash memory technology to store ...

  • email archiving

    Email archiving (also spelled e-mail archiving) is a systematic approach to saving and protecting the data contained in email ...

  • RAID (redundant array of independent disks)

    RAID (redundant array of independent disks) is a way of storing the same data in different places on multiple hard disks to ...

SearchSolidStateStorage

  • M.2 SSD

    An M.2 SSD is a solid-state drive (SSD) that conforms to a computer industry specification written for internally mounted storage...

  • NVMe (non-volatile memory express)

    NVMe (non-volatile memory express) is a host controller interface and storage protocol to enable a solid-state drive to use the ...

  • SSD RAID (solid-state drive RAID)

    SSD RAID (solid-state drive RAID) is a methodology commonly used to protect data by distributing redundant data blocks across ...

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close