A firefighter jumps horizontally from a burning building with an initial speed of 1.5 m/s. At what time is the angle between his velocity and acceleration vectors the greatest?
Correct answer: A. The instant he jumps.
- A. The instant he jumps.
- B. When he reaches terminal velocity
- C. Halfway through his fall
- D. Right before he lands on the ground
Explanation
When the firefighter jumps horizontally from the building, his initial velocity is purely horizontal (since no vertical component is mentioned).At the moment of jumping, the acceleration due to gravity acts vertically downward. The angle between the horizontal velocity and vertical acceleration vectors is 90 degrees, making it the greatest angle between these vectors.As the firefighter falls, the angle between the velocity and acceleration vectors decreases until he reaches the maximum speed vertically downward when the angle is 0 degrees, aligning with the acceleration due to gravity.
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