Final answer:
The student's physics question asks to calculate the height from which a life preserver was released from a hovering rescue helicopter. Using the provided initial velocity, time to reach the water, and assuming acceleration due to gravity, the calculation results in a height of about 18.4 meters above the water.
Step-by-step explanation:
The question presented is related to the subjects of physics and involves calculating the height from which an object is dropped, considering the effects of gravity and initial velocity.
Specifically, it invokes concepts from mechanics, a branch of physics that deals with the motion of objects and the forces acting upon them.
Answer (Part a): Knowns in the Problem
- Initial Velocity (v0): 1.40 m/s (downward)
- Time (t): 1.8 seconds
- Acceleration due to gravity (g): 9.8 m/s2
Answer (Part b): Calculating the Height
To find the height (h) from which the life preserver was released, we need to use the kinematic equation for uniformly accelerated motion:
h = v0 × t + ½ × g × t2
Plugging in the known values:
h = 1.40 m/s × 1.8 s + ½ × 9.8 m/s2 × (1.8 s)2
h = 2.52 m + 15.876 m
h = 18.396 m
The preserver was released from approximately 18.4 meters above the water.