Sadiq dropped his watch into a lake. The depth of the lake is 5 meters. Sadiq can dive down towards the bottom of the lake at a speed of 2 meters per second, but can swim upwards at a rate of 1 meter per second. How long will it take Sadiq to get his watch and return to the surface of the lake?
going down: 5/2 seconds
going up: 5/1 seconds
so, down+up = ?
To calculate the time it will take Sadiq to get his watch and return to the surface of the lake, we need to determine the time it takes him to reach the bottom of the lake and then the time it takes him to swim back to the surface.
1. Time to reach the bottom:
The depth of the lake is 5 meters, and Sadiq can dive down at a speed of 2 meters per second. To calculate the time it takes to reach the bottom, we divide the depth by the diving speed: 5 meters / 2 meters per second = 2.5 seconds.
2. Time to swim back to the surface:
Once Sadiq has retrieved his watch from the bottom of the lake, he needs to swim back to the surface. Sadiq's swimming speed is 1 meter per second, and the distance he needs to swim is also 5 meters (which is the same as the depth of the lake). To calculate the time it takes to swim back to the surface, we divide the distance by the swimming speed: 5 meters / 1 meter per second = 5 seconds.
3. Total time:
To determine the total time, we add the time it takes to reach the bottom (2.5 seconds) to the time it takes to swim back to the surface (5 seconds): 2.5 seconds + 5 seconds = 7.5 seconds.
Therefore, it will take Sadiq 7.5 seconds to get his watch and return to the surface of the lake.