Kavita found that the clock minute hand was on 3 and hour hand was on ...
Initial Positions of Hands
- The minute hand is on 3, which corresponds to 15 minutes past the hour.
- The hour hand is on 7, indicating it is 7 o'clock.
Final Positions of Hands
- The minute hand moves to 9, which corresponds to 45 minutes.
- The hour hand is now on 3, indicating it is 3 o'clock.
Time Elapsed
- From 7:15 to 3:45, the total time elapsed is 8 hours and 30 minutes (or 8.5 hours).
Movement of Hour Hand
- The hour hand moves at a rate of 30 degrees per hour (360 degrees/12 hours).
- In 8.5 hours, the movement is:
Angle = Time × Rate
Angle = 8.5 hours × 30 degrees/hour
Angle = 255 degrees
Understanding the Angle
- The hour hand moved from 7 to 3, which is a movement of 6 hour marks on the clock (7 to 8, 8 to 9, 9 to 10, 10 to 11, 11 to 12, and 12 to 1).
- Each hour mark represents an angle of 30 degrees. Therefore, the angle from 7 to 3 is:
Angle = 6 marks × 30 degrees/mark = 180 degrees
Conclusion
- The hour hand moved 255 degrees in total, but the effective angle from the initial position to the final position is 180 degrees.
- Therefore, the angle the hour hand covers during this period is **180 degrees**.
To make sure you are not studying endlessly, EduRev has designed UPSC study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in UPSC.