A body under free fall is an example of a body with uniform velocity, when air resistance is ignored.
True
False
The correct answer and explanation is:
False
A body in free fall is not an example of a body with uniform velocity, even when air resistance is ignored. This is because, under the influence of gravity, the velocity of the body continuously increases as it falls.
When an object is released from rest or falls under gravity, it experiences an acceleration due to Earth’s gravitational pull. The acceleration due to gravity is approximately 9.8 m/s² near the Earth’s surface. This means that for every second the object falls, its velocity increases by approximately 9.8 meters per second.
Initially, when the object starts falling, its velocity is zero, but as time passes, the object accelerates, and its velocity increases. This increase in velocity is a result of the constant acceleration from gravity, not uniform motion. If the object were moving with uniform velocity, it would mean that the velocity remains constant over time, which is not the case here.
If air resistance is neglected, the only force acting on the object is gravity. This causes the object to continuously accelerate until it reaches the ground, assuming no other forces are at play. The velocity at any given time is the result of this continuous acceleration.
In the presence of air resistance, the object would eventually reach terminal velocity, where the force of gravity is balanced by the force of air resistance, and the object would fall at a constant velocity. However, in the idealized case of free fall with no air resistance, the velocity increases without bound as the object accelerates.
Thus, the body in free fall under gravity does not have uniform velocity, as it is constantly accelerating and its speed is continuously increasing.