A skydiver jumps out of a plane and begins to accelerate. His speed increases to 20 m/s then 30 m/s . His acceleration slows until he reaches a constant speed of 50 m/s which statement correctly describes his kinetic energy during this time.
The correct statement is that his kinetic energy increases from 0 to a maximum value and then remains constant at that maximum value.
As the skydiver jumps out of the plane, his speed initially increases from 0 to 20 m/s, which means his kinetic energy is increasing. Then, his speed further increases to 30 m/s, resulting in a higher kinetic energy. However, once he reaches a constant speed of 50 m/s, his kinetic energy remains constant at this maximum value since kinetic energy is directly proportional to the square of the velocity.
The kinetic energy (KE) of an object is given by the equation KE = 1/2 * mass * velocity^2. In this case, the skydiver is experiencing changes in velocity, so let's analyze the kinetic energy at each stage:
1. When the speed increases from 0 m/s to 20 m/s, the kinetic energy of the skydiver increases according to the equation KE = 1/2 * mass * velocity^2. Since the velocity is increasing, the kinetic energy also increases.
2. When the speed further increases from 20 m/s to 30 m/s, the kinetic energy continues to increase because the velocity is still increasing.
3. Finally, when the speed reaches a constant value of 50 m/s, the kinetic energy becomes constant. At this point, the skydiver's velocity is no longer changing, so the kinetic energy becomes constant.
Therefore, the statement that correctly describes the skydiver's kinetic energy during this time is: The kinetic energy increases until the speed reaches 50 m/s and then remains constant.
To determine the correct statement about the skydiver's kinetic energy during this time, we need to understand the relationship between kinetic energy and speed.
Kinetic energy (KE) is the energy possessed by an object due to its motion. It is given by the equation KE = (1/2)mv^2, where m represents the mass of the object and v represents its velocity/speed.
Let's analyze the scenario step by step:
1. Initially, when the skydiver jumps out of the plane, his speed increases from 0 m/s to 20 m/s. During this period, his kinetic energy increases because kinetic energy is directly proportional to the square of the velocity. Therefore, his kinetic energy is increasing.
2. As the skydiver's speed further increases from 20 m/s to 30 m/s, his kinetic energy continues to increase because the square of 30 is greater than the square of 20. So, his kinetic energy further increases.
3. When the skydiver reaches a constant speed of 50 m/s, it means his acceleration has stopped. At this point, his speed remains constant, and hence, his kinetic energy also remains constant, as long as his speed does not change.
Therefore, the correct statement is: His kinetic energy remains constant while he travels at a constant speed of 50 m/s.