No, acceleration refers to a change in an object's velocity, which can either be a speed up (positive acceleration) or a slow down (negative acceleration or deceleration). If an object is decelerating, its velocity is decreasing over time.
This would indicate negative acceleration, which would mean that the object in question is speeding up.
Yes, an object can have negative velocity and negative acceleration if it is moving in the opposite direction of the positive axis. This would mean the object is both moving backwards and its speed is decreasing.
It is not true. It means that the object MIGHT be decelerating but not "always" (as your friend says). Instead, think of it this way... We start by clarifying that there is no such thing as "negative acceleration" per se. That is, that acceleration is a vector composed of an absolute value scalar and a direction. So "negative acceleration" actually refers to an acceleration which just happens to be in the negative direction of whatever coordinate system you've chosen to define for the particular problem. We define a coordinate system (for a two dimensional universe to keep things simple) with positve/negative x and y. If the object starts out already moving in the positive X direction, then to apply an acceleration in the negative direction would mean there is deceleration. If the object is stationary or moving in the negative X direction, then applying an acceleration in the negative X direction would actually be accelerating the object. In other words, the reference from has to stay constant for there to be meaningful discourse on the subject. By the same note, even moving in the positive X direction, if the object is acclerated in the negative Y direction then the object is actually accelerating.
False. It means it is slowing Down!
An object can still be moving with zero acceleration if it is moving at a constant velocity. When acceleration is zero, the object's velocity remains constant, meaning it continues to move at the same speed and in the same direction without any change in speed or direction.
This would indicate negative acceleration, which would mean that the object in question is speeding up.
Yes, an object can have negative velocity and negative acceleration if it is moving in the opposite direction of the positive axis. This would mean the object is both moving backwards and its speed is decreasing.
It is not true. It means that the object MIGHT be decelerating but not "always" (as your friend says). Instead, think of it this way... We start by clarifying that there is no such thing as "negative acceleration" per se. That is, that acceleration is a vector composed of an absolute value scalar and a direction. So "negative acceleration" actually refers to an acceleration which just happens to be in the negative direction of whatever coordinate system you've chosen to define for the particular problem. We define a coordinate system (for a two dimensional universe to keep things simple) with positve/negative x and y. If the object starts out already moving in the positive X direction, then to apply an acceleration in the negative direction would mean there is deceleration. If the object is stationary or moving in the negative X direction, then applying an acceleration in the negative X direction would actually be accelerating the object. In other words, the reference from has to stay constant for there to be meaningful discourse on the subject. By the same note, even moving in the positive X direction, if the object is acclerated in the negative Y direction then the object is actually accelerating.
False. It means it is slowing Down!
An object can still be moving with zero acceleration if it is moving at a constant velocity. When acceleration is zero, the object's velocity remains constant, meaning it continues to move at the same speed and in the same direction without any change in speed or direction.
No, acceleration and momentum are not the same. Acceleration refers to the rate of change of an object's velocity, while momentum is the product of an object's mass and velocity. Acceleration measures how quickly an object's velocity is changing, while momentum is a property that depends on both an object's mass and how fast it is moving.
Yes. "Acceleration" does not mean "speeding up". It means any change in speedor direction of motion. If the body is moving on a curve, even at a constant speed,its direction is changing, so there is acceleration.
When the forces on an object add up to zero, the object's acceleration is zero. Thatmeans the speed or direction of its motion doesn't change. It does not mean thatthe object isn't moving. A moving object would just keep moving at a constantspeed in a straight line.
Acceleration doesn't mean "speeding up". It only means that the speed or direction of motion, or both, are changing. Speeding up is positive acceleration in the direction you're moving. Slowing down is negative acceleration in the direction you're moving, or positive acceleration in the opposite direction.
A positive slope on a velocity-time graph indicates that the object is moving in the positive direction (e.g., right or up) and experiencing a constant acceleration. The steeper the slope, the greater the acceleration of the object.
I am not sure what you mean by reversing a zero acceleration. An object's acceleration can, of course, change over time.
Yes, it can happen. when the velocity is momentarily zero while an object is changing from moving in the positive direction motion to the negative direction; the object obviously will stop at one point, but will still have a constant acceleration.