speed increases, when acceleration and velocity decrease. true or false statement?
speed is a scalar quantity, so true?
The statement is actually false. Let me explain why.
Speed is a scalar quantity that represents how fast an object is moving. It is defined as the distance an object travels per unit of time. Speed does not depend on the direction of motion and only considers the magnitude of velocity.
Acceleration, on the other hand, is the rate at which an object's velocity changes. It is a vector quantity because it includes both the magnitude and direction of velocity change. Acceleration can be positive or negative, depending on whether an object is speeding up or slowing down.
When an object's acceleration is zero, it means that its velocity is not changing. In this case, if the speed is also constant, then the object is moving at a constant speed.
However, if the acceleration is non-zero, it means that the object's velocity is changing. If the acceleration is positive, the object is speeding up, and if the acceleration is negative, the object is slowing down. In both cases, the speed of the object can increase or decrease, depending on the direction of the acceleration. So, velocity changes, but it does not necessarily mean that speed decreases.
Therefore, the statement "speed increases when acceleration and velocity decrease" is not true.