Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Acceleration due to Gravity on Other Planets01:24

Acceleration due to Gravity on Other Planets

4.6K
The gravitational acceleration of an object near the Earth's surface is called the acceleration due to gravity. It can be measured by conducting simple experiments on Earth. However, such an experiment is impossible to conduct on the surface of other planets.
Astronomical observations are thus used to measure the acceleration due to gravity on other planets. This can be determined by observing the effect of a planet's gravity on objects close to it. The crucial factor that helps in this...
4.6K
Weightlessness01:01

Weightlessness

6.3K
When an object is dropped, it accelerates toward the center of the Earth. If the net external force on the object is its weight, it is said to be in free fall; that is, the only force acting on the object is gravity. Galileo was instrumental in showing that, in the absence of air resistance, all objects fall with the same acceleration g. However, when objects on the Earth fall downward, they are never truly in free fall, because there is always some upward resistance force from the air acting...
6.3K
Gravitational Potential Energy for Extended Objects01:07

Gravitational Potential Energy for Extended Objects

1.6K
Consider a system comprising several point masses. The coordinates of the center of mass for this system can be expressed as the summation of the product of each mass and its position vector divided by the total mass:
1.6K
Variation in Acceleration due to Gravity near the Earth's Surface01:20

Variation in Acceleration due to Gravity near the Earth's Surface

2.6K
An object's apparent weight is its weight measured by a spring balance at its location. It is different from its true weight, the force with which the Earth pulls it, because of the Earth's rotation. Mathematically, an object's apparent weight equals its true weight minus the centripetal force that keeps it in a circular motion along with the Earth's surface every 24 hours.
The difference between the true and apparent weights is proportional to the square of the Earth's...
2.6K
Rocket Propulsion in Gravitational Field - II01:03

Rocket Propulsion in Gravitational Field - II

2.5K
A rocket's velocity in the presence of a gravitational field is decreased by the amount of force exerted by Earth's gravitational field, which opposes the motion of the rocket. If we consider thrust, that is, the force exerted on a rocket by the exhaust gases, then a rocket's thrust is greater in outer space than in the atmosphere or on a launch pad. In fact, gases are easier to expel in a vacuum.
A rocket's acceleration depends on three major factors, consistent with the...
2.5K
Rocket Propulsion in Gravitational Field - I01:20

Rocket Propulsion in Gravitational Field - I

3.0K
Rockets range in size from small fireworks that ordinary people use to the enormous Saturn V that once propelled massive payloads toward the Moon. The propulsion of all rockets, jet engines, deflating balloons, and even squids and octopuses are explained by the same physical principle: Newton's third law of motion. The matter is forcefully ejected from a system, producing an equal and opposite reaction on what remains.
The motion of a rocket in space changes its velocity (and hence its...
3.0K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Biohybrid cochlear implants: neural interfaces, regenerative pathways, and translational benchmarks.

Journal of neuroengineering and rehabilitation·2026
Same author

Fluid-regulating hormones and plasma volume during 60 days of head-down bed rest with exercise during artificial gravity (BRACE).

Journal of applied physiology (Bethesda, Md. : 1985)·2026
Same author

Exercise during artificial gravity preserves cardiorespiratory fitness but not orthostatic tolerance following 60 days of head-down bed rest (BRACE).

Journal of applied physiology (Bethesda, Md. : 1985)·2025
Same author

Author Correction: Increasing seated reaction forces with lower body negative pressure.

NPJ microgravity·2025
Same author

Uncloggable ventriculoperitoneal shunt system for hydrocephalus via an integrated soft robotic device: CLEARS device.

Biomedical microdevices·2025
Same author

Increasing seated reaction forces with lower body negative pressure.

NPJ microgravity·2025

Related Experiment Video

Updated: Nov 17, 2025

Mimicking a Space Mission to Mars Using Hindlimb Unloading and Partial Weight Bearing in Rats
05:54

Mimicking a Space Mission to Mars Using Hindlimb Unloading and Partial Weight Bearing in Rats

Published on: April 4, 2019

11.0K

Generating waist area-dependent ground reaction forces for long-duration spaceflight.

Neeki Ashari1, Mitchell Kong1, Alisha Poudel2

  • 1Department of Orthopaedic Surgery, United States; Department of Bioengineering, United States.

Journal of Biomechanics
|February 13, 2021
PubMed
Summary

Astronauts

Keywords:
Artificial gravityGround reaction forceLower body negative pressureMicrogravitySpaceflight

More Related Videos

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study
08:40

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study

Published on: November 11, 2022

1.3K
Reduced-gravity Environment Hardware Demonstrations of a Prototype Miniaturized Flow Cytometer and Companion Microfluidic Mixing Technology
13:59

Reduced-gravity Environment Hardware Demonstrations of a Prototype Miniaturized Flow Cytometer and Companion Microfluidic Mixing Technology

Published on: November 13, 2014

14.0K

Related Experiment Videos

Last Updated: Nov 17, 2025

Mimicking a Space Mission to Mars Using Hindlimb Unloading and Partial Weight Bearing in Rats
05:54

Mimicking a Space Mission to Mars Using Hindlimb Unloading and Partial Weight Bearing in Rats

Published on: April 4, 2019

11.0K
Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study
08:40

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study

Published on: November 11, 2022

1.3K
Reduced-gravity Environment Hardware Demonstrations of a Prototype Miniaturized Flow Cytometer and Companion Microfluidic Mixing Technology
13:59

Reduced-gravity Environment Hardware Demonstrations of a Prototype Miniaturized Flow Cytometer and Companion Microfluidic Mixing Technology

Published on: November 13, 2014

14.0K

Area of Science:

  • Space medicine
  • Biomechanics
  • Human physiology

Background:

  • Prolonged microgravity weakens astronaut bones and muscles, increasing fracture risk.
  • Lower body negative pressure (LBNP) simulates gravity to counteract muscle and bone loss.
  • Understanding LBNP's effectiveness is crucial for long-duration spaceflight.

Purpose of the Study:

  • To investigate if increasing waist cross-sectional area (CSA) enhances ground reaction forces (GRFs) during LBNP.
  • To determine the relationship between waist CSA, negative pressure, and simulated gravitational force.
  • To explore a novel LBNP technique for mitigating microgravity's effects.

Main Methods:

  • Six healthy subjects participated in simulated microgravity using LBNP.
  • Two waist CSA conditions were tested: original and enlarged.
  • Ground reaction forces were measured at varying negative pressures (0-50 mmHg).

Main Results:

  • Larger waist CSA generated significantly greater GRFs at equivalent negative pressures.
  • At -50 mmHg, larger CSA produced 1.46 ± 0.31 G, compared to 1.18 ± 0.31 G for original CSA.
  • Simulated bodyweight of one G was achieved at lower negative pressures with the enlarged waist CSA.

Conclusions:

  • Increasing waist CSA during LBNP amplifies simulated gravitational forces (GRFs).
  • This technique may offer a more efficient way to strengthen astronaut musculoskeletal systems.
  • The novel method could reduce cardiovascular strain and conserve spacecraft power.