A river flows at a speed of 4 km/h. If a boat can travel at 10 km/h in still wat
Practice Questions
Q1
A river flows at a speed of 4 km/h. If a boat can travel at 10 km/h in still water, how long will it take the boat to travel 12 km upstream?
1 hour
2 hours
1.5 hours
3 hours
Questions & Step-by-Step Solutions
A river flows at a speed of 4 km/h. If a boat can travel at 10 km/h in still water, how long will it take the boat to travel 12 km upstream?
Step 1: Identify the speed of the river, which is 4 km/h.
Step 2: Identify the speed of the boat in still water, which is 10 km/h.
Step 3: Calculate the effective speed of the boat when going upstream by subtracting the river's speed from the boat's speed: 10 km/h - 4 km/h = 6 km/h.
Step 4: Identify the distance the boat needs to travel upstream, which is 12 km.
Step 5: Use the formula for time, which is Time = Distance / Speed.
Step 6: Plug in the values: Time = 12 km / 6 km/h.
Step 7: Calculate the time: 12 km / 6 km/h = 2 hours.
Relative Speed – Understanding how to calculate effective speed when moving against a current.
Time Calculation – Using the formula Time = Distance / Speed to find the time taken for a journey.
