Suppose you are told that the moon travels around Earth at a constant speed.

Question

CAN YOU ALSO SAY THAT ITS VELOCITY IS CONSTANT? WHY OR WHY NOT?

Answer 1

No, velocity is not constant in Newtonian physics.

Velocity is speed in a certain direction - if you change direction, but not speed, your velocity still changes (just as if you change speed but not direction, velocity changes).

Note that in General Relativity, we say that the moon is moving in a straight line in curved space, so it's velocity wouldn't change - but I doubt that's the answer they are looking for here.

Note that the moon does not move at a constant speed (forgetting the gravitational of the sun and other bodies), since its orbit is not a perfect circle.

Answer 2

Hmmm....I'm thinking this one over....

Well, it seems to me that velocity is a combination of

the components speed and direction and can be

expressed as a vector.

So my answer would be no. (although as basic terms most

people would assume that the speed would equal the

velocity).

Answer 3

wow the moon travels around the earth. Yes velocity is wind speed. so if you have constant speed they you have constant velocity.  

Answer 4

No. Velocity is a vector quantity (it has a direction), while speed is a scalar quantity (it only has a  magnitude, but no direction).

As the cross product of velocity vector and radius is constant for any orbital object, and the magnitude of the velocity vector (which is equal to speed) is constant, but the radius vector changing over time (as the position of the moon changes), the velocity vector must change (but with constant magnitude)

Answer 5

Yes you can say that. If you could not say that it would mean that the moon will soon be raising and going down at verry weird times. (i think)

Answer 6

velocity is a vector and it depends on both magnitude and direction. if any one of them changes,velocity vector changes.if both of them change,then also velocity changes.magnitude of velocity vector is speed.as it moves around earth,its velocity direction always changes and velocity vector can't remain same even if speed remains constant.

Answer 7

it does not have a constant speed because according to our physics, the moon revolves around the earth in circular motion thus it change direction because a circular path is not included in to the directions. and because it change in direction, its changing in velocity.

Answer 8

No.  The direction is constantly changing, since it is moving in a circle rather than a straight line.

Answer 9

Yes.  Velocity accounts for both speed and direction.  You're already given that the moon travels at a constant speed.    As long as the moon stays in it's path around the earth, direction is constant, so velocity is constant

Answer 10

The only time when a celestial body's speed can be constant is when it orbits the object it is orbiting in a perfect circle, and maintains a constant, exact distance from the object it is orbiting. All planets in the solar system have a somewhat elliptical orbit, no matter how small it is.

The closer an object gets to the object it is orbiting, the faster it goes. That follows Kepler's law of planetary motion. The farther it is from the object, obviously the slower it will be going. So no, the velocity isn't constant.

Answer 11

depends on what velocity is

Answer 12

No. An object moving in a circle has constantly changing velocity. Velocity is a vector quantity, consisting of speed and direction. Motion in a circle involves constant changing direction, ergo constantly changing velocity.