Speed can be zero (an object can be stationary), but the question often arises because average speed can't be zero for a moving body over time, and instantaneous speed (though momentarily zero at peaks/troughs) is tied to movement, making "zero speed" a limit case for rest, not a state for something in motion, with the speed of light being a fundamental constant limit, not a zero speed. The core misunderstanding often lies between speed (how fast) and velocity (speed + direction), or average vs. instantaneous values.
Complete answer:
The speed of a body can never be zero and this can be justified with the help of the two reason: One reason is that it is a scalar quantity and scalar quantity cannot be negative, and the explanation is done in the hint. Second reason can be justified by its formula.
Assertion : Average velocity can't be zero in case of uniform acceleration. Reason : For average velocity to be zero, a non zero velocity should not remain constant.
Yes, that's correct. Speed, being a scalar quantity, is always positive or zero. It measures how fast an object is moving, regardless of the direction.
Average speed can be zero only if the total distance covered is zero (e.g., if the object does not move at all).
Speed can be positive, negative or zero.
Note The point to be noted, we should keep in mind that average speed is a scalar quantity and average velocity is a vector quantity. The average velocity of a moving object can be zero in the case of a circular path as displacement will be zero but average speed cannot be zero for a moving object.
For example, if a car sits at rest its velocity is, by definition, equal to zero.
Yes. When a body is thrown vertically upwards it has zero velocity at its highest point . Even then it has acceleration equal to the acceleration due to gravity in vertical motion .
Acceleration of an object can be zero when it is moving with a constant velocity. Since velocity is constant, there will be no change in velocity and so there will be no acceleration.
A key consequence is that absolute zero cannot be reached, since removing heat becomes increasingly inefficient and entropy changes vanish. This unattainability principle means no physical process can cool a system to absolute zero in a finite number of steps or finite time.
When an object moves at constant speed, the distance covered in equal intervals of time remains the same. There is no change in velocity, and the acceleration is zero. Constant speed does not imply constant velocity if the object changes direction, such as in circular motion.
In the simple harmonic motion during the motion, at the extreme positions, the velocity of the body is zero but the acceleration is highest. for example, the simple harmonic motion of spring and the simple harmonic motion of Pendulum. Therefore, a body can have zero velocity and finite acceleration.
Distance is a measure of how far apart two points or objects are from each other. If two points are exactly at the same location, then the distance between them is zero. For example, the distance between a point and itself is always zero.
1: Speed is a scalar quantity. It does not change at all with direction changes; therefore, it has magnitude only. If it were a vector quantity, it would change as direction changes (even if its magnitude remained constant).
**Understanding the Assertion (A)**: - The assertion states that when the velocity of an object is zero at an instant, the acceleration need not be zero at that instant. - This is true because acceleration is defined as the rate of change of velocity.
Yes, a body has constant speed as well as variable velocity. Consider an example: A particle moving in a circular path with a uniform circular motion.
As it passes the starting point, its average velocity is zero (because its displacement is zero), but the acceleration is non-zero. An object can have an instantaneous velocity of zero, but still have non-zero acceleration.
Yes, an object in uniform circular motion is accelerating but its speed neither decreases not increases .
Answer and Explanation:
At the maximum height, there is no motion along the vertical axis.
People mistakenly think the final velocity for a falling object is zero because objects stop once they hit the ground. In physics problems, the final velocity is the speed just before touching the ground.
For example, if you're running on a track, your speed is how fast you are running, while your velocity is how fast you are running in a certain direction. Imagine running around a track in a circle. You could be running really fast, but your velocity would be zero because you're not going in any particular direction.
Changes in speed are expressed in multiples of gravitational acceleration, or 'G'. Most of us can withstand up to 4-6G. Fighter pilots can manage up to about 9G for a second or two. But sustained G-forces of even 6G would be fatal.
A : Average velocity can be zero, but average speed of a moving body can not be zero in any finite time interval.
No, distance cannot be zero when displacement is not zero.