zero velocity =)
Free fall.
Because there are no contact forces acting on us. Gravity is the only acting on us. A body experiences weightlessness when gravity is the only force acting on it.
Centripetal force wants to move something towards the centre. So in a satellites case that would be the Gravity of the Earth. If you had a rock tied to a string you were spinning around, the Centripetal Force would be the tension in the string acting towards the centre.
gravity
Mass is conserved which means that a body will have the same mass wherever it goes. But at the centre of a masive sphere the body has no gravity acting on it so its weight is zero. At an intermediated radius the force on it is obviously less than at the surface, and Isac Newton proved that a body at a given distance inside a sphere feels a gravitational force from a sub-sphere of radius equal the distance of the body from the centre. In other words the body feels no gravity from the shell outside its own radius.
If you want to define total centre of gravity of a person, you must know:the mass of each body segmentsthe x, y and z coordinate of centre of gravity of each body segment (3D motion)
Free falling.
During motion in a vertical circle, the force of gravity (weight of the object) is in the same direction as the motion for half the time and in the opposite direction for the rest.For a body moving in a horizontal circle, gravity is acting orthogonally to the motion at all times.During motion in a vertical circle, the force of gravity (weight of the object) is in the same direction as the motion for half the time and in the opposite direction for the rest.For a body moving in a horizontal circle, gravity is acting orthogonally to the motion at all times.During motion in a vertical circle, the force of gravity (weight of the object) is in the same direction as the motion for half the time and in the opposite direction for the rest.For a body moving in a horizontal circle, gravity is acting orthogonally to the motion at all times.During motion in a vertical circle, the force of gravity (weight of the object) is in the same direction as the motion for half the time and in the opposite direction for the rest.For a body moving in a horizontal circle, gravity is acting orthogonally to the motion at all times.
A force acting on a body accelerates it in the direction of the force.
A body in uniform motion has no net force acting on it. That means that either there are no forces at all, or else that all the forces acting on it add up to zero.
Gravity is a force and any force acting on a body changes its velocity in the direction of the force.
Free Fall
No; gravity will continue acting on your body. If there was no force acting on your body while in space (let's say an orbiting satellite), the satellite would fly out of Earth's orbit and just wander off forever, but that doesn't happen - so gravity has to be acting on the satellite and your body as well!
If we have a force acting on a body and we know what that force is, and we also know that the force is gravity, we can solve because we know the force gravity exerts on a mass. If we take the total force acting on the body and divide it by the force of gravity per one unit of mass, we can find the number of units of mass that cause gravity to act on the object. We have 1033 Newtons of force acting on the object. Gravity pulls down with a force of 9.8 Newtons on 1 kilogram of mass. Our 1033 Newtons divided by 9.8 Newtons per kilogram = 105.41 kilograms
Because there are no contact forces acting on us. Gravity is the only acting on us. A body experiences weightlessness when gravity is the only force acting on it.
"The condition of equilibrium or motion of a rigid body is remain unchanged, if a force acting on the rigid body is replaced by another force of the same magnitude and same direction but, acting anywhere along the same line of action."
A force acting on the body, along its line of motion.
Gravity does not cause a body in motion to stop.This can be accomplished either by friction or by a brick wall.