A student runs from the ground floor to the fourth floor of a school building. Class 9

A student runs from the ground floor to the fourth floor of a school building. Class 9

Question 1.

A student runs from the ground floor to the fourth floor of a school building to collect a book and then comes down to their classroom on the second floor. If the height of each floor is 3 m, find: Class 9

(i) the total vertical distance travelled, and

(ii) their displacement from the starting point.

Answer:

Setting up the problem:

1. Ground floor = 0 m (starting point)
2. Each floor height = 3 m
3. 1st floor = 3 m, 2nd floor = 6 m, 3rd floor = 9 m, 4th floor = 12 m

Journey:

1. Ground floor → 4th floor: travels upward = 12 m
2. 4th floor → 2nd floor: travels downward = 12 - 6 = 6 m

Part (i): Total vertical distance travelled

Total distance = distance going up + distance coming down = 12 m + 6 m = 18 m

Part (ii): Displacement from starting point

Starting point = Ground floor = 0 m Ending point - 2nd floor = 6 m

Displacement = final position — initial position = 6

m - 0 m = 6 m (upward direction)

The displacement is 6 m in the upward direction, because the student started at the ground floor and ended at the 2nd floor, which is 6 m above the starting point. The direction is upward.