Acceleration means the velocity changes. Velocity is made up of speed and a direction, so if only the direction changes, the velocity still changes, and therefore there is acceleration. The typical example is moving around in a circle.
"Acceleration" does not mean "speeding up". It means any change in the
speed or direction of an object's motion. So the object is accelerating if it's
speeding up, slowing down, or moving on a curve ... even at constant speed.
If an object was in a circular orbit under the influence of some centralizing force, such as gravity, or magnetism, or electro-static, or even strong nuclear or weak nuclear - then it has a constant speed (not velocity, angular velocity) and a radial acceleration equal to v2/r.
"Velocity" means a speed and the direction it's in.
"Acceleration" means any change in velocity ... the speed, or the direction, or both.
So ...
-- If you keep going in the same direction but change your speed, then
your velocity has changed, and that's called acceleration.
-- If you keep going at the same speed but change your direction, then
your velocity has changed, and that's called acceleration.
-- If your speed changes and your direction also changes, then your velocity
has changed, and that's called acceleration.
-- If there's no acceleration, then you can only be moving at a constant speed
in a straight line. That's the only kind of motion you can have without changing
velocity.
That can't happen. If there is any acceleration at all, then velocity is not constant.
It depends what the situation is. If an object is falling, the weight of the object, which is determined by the object's mass and the gravity, is the force causing it to accelerate. If you're talking about a box being pushed, you could have a person pushing it, which causes it to accelerate, but you also must take into account the force of friction combatting the applied force.
If the box is sliding along at a constant speed, the net force acting on the box is zero.If the net force was not zero, the box would either be speeding up or slowing down.Non-zero net forces acting on objects cause the objects to accelerate. Therefore, if the net forces is not zero, the velocity of the object could not be constant.
The first law deals with forces and changes in velocity. For just a moment, let us imagine that you can apply only one force to an object. That is, you could choose push the object to the right or you could choose to push it to the left, but not to the left and right at the same time, and also not up and to the right at the same time, and so on. Under these conditions the first law says that if an object is not pushed or pulled upon, its velocity will naturally remain constant. This means that if an object is moving along, untouched by a force of any kind, it will continue to move along in a perfectly straight line at a constant speed.
Well, if you do that for a while, you could certainly raise a sweat, and you would say that you've done a lot of work. But in the strict Physics definition of "work", none of it has been done to the object you carried. The strict definition is: Force acting through a distance. Referring to the object you carry: -- You don't move it vertically. You just hold it there against the force of gravity, but your vertical force doesn't move it up or down. So no work is done vertically. -- Horizontally, the speed is constant. No force is required to maintain a constant speed, so no work is done horizontally either.
There is no constant ratio for image size to object size It depends on, 1. Image size 2. Sensor specifications (ex: Focal length of the camera) 3. Camera to Object distance 4. Acquisition angle (Theta) 5. Light focusing 6. Need some Known object values for determine unknown object size etc...
The question is inherantly flawed. A car traveling at a constant speed cannot accelerate, if it could it's speed would not be constant. "Constant speed" means that speed is not increasing or decreasing but remain consistent over time. For example, if you cover 10 feet during each second, your speed is constant. "Constant velocity" implies constant speed, but it has an additional constraint: you can't change your direction. If you travel constantly at 10 feet per second in a straight line, then your speed is constant and your velocity is constant. But if you travel constantly at 10 feet per second in a wiggly line (or a circle, or anything not straight), then your speed is constant but your velocity is NOT constant. If you travel at a constant speed but change direction, velocity is changed. Or if you travel in the same direction but change the speed, velocity is changed. Average speed is is easier: distance/time So, your question should read: Why can a car traveling at an average speed accelerate, but a car traveling at constant speed cannot? Or Why am I asking the wrong questions?
No. Acceleration is defined as the rate of change of velocity. If velocity is constant, then its rate of change is zero. --------------------------------------------------------------------------- Another contributor obfuscated: If we were to get really picky with our vectors we could say that an object could have constant velocity in the x-y plane and still accelerate in the z-axis. Also a system of objects could have a net-velocity in 3-D space and still have a radial acceleration. A solar system traveling through space at constant velocity will have a radial acceleration, for each component part of the system, around the gravitational center of mass of the system.
Not accelerating. It could be stationary or moving at a constant speed.
Constant, perhaps scalar constant. Since you could have a constant vector or other object, as well.
We know that that is the way our Universe works; WHY the Universe was designed that way, or why it happens to be that way, is normally not known.In this case, with a different law for velocity, lots of the physics we know would be drastically different - for example, conservation of energy, conservation of momentum, and conservation of angular momentum could all be violated.
When the forces on an object are unbalanced the changes that could happen are the object speeds up, or slows down. And it can changes direction.
Mass is defined as resistance to acceleration, so one could measure how much force is needed to accelerate the object.
You can't. The net force simply means that the acceleration is zero. It could be at rest, or the object could be moving at a constant velocity.
An object maintains a constant velocity when the net force acting upon that object is zero. Therefore, a force pushing against the object that exactly opposes the force(s) due to friction (in both magnitude and direction) will result in a net force of zero, and the object will maintain a constant speed.
if velocity is constant, that means then the net acceleration acting on the object is equal to zero
An object with no forces in it will eventually stop moving, according to Aristotle. Aristotle was a Greek philosopher. He was born in 384 BCE.
No. Velocity is a 'vector', which means it's a measurement that has both magnitude and direction. The magnitude is what we usually call the 'speed'. For an object moving in a circle, it could have constant speed ... the velocity could have constant magnitude ... but there's no way the whole velocity vector could be constant, because the direction is always changing. Constant velocity is very easy to recognize ... the object is moving at a steady speed, in a straight line.