A river is 300 m wide. If a person swims across the river at a speed of 2 m/s an
Practice Questions
Q1
A river is 300 m wide. If a person swims across the river at a speed of 2 m/s and the river flows at 1 m/s, how long will it take to cross the river? (2020)
150 s
100 s
200 s
300 s
Questions & Step-by-Step Solutions
A river is 300 m wide. If a person swims across the river at a speed of 2 m/s and the river flows at 1 m/s, how long will it take to cross the river? (2020)
Step 1: Identify the width of the river, which is 300 meters.
Step 2: Identify the swimming speed of the person, which is 2 meters per second.
Step 3: Understand that the river's flow speed (1 m/s) does not affect the time taken to swim across the width of the river directly.
Step 4: Use the formula for time, which is Time = Distance / Speed.
Step 5: Plug in the values: Distance is 300 meters and Speed is 2 meters per second.
Step 6: Calculate the time: Time = 300 m / 2 m/s = 150 seconds.
Relative Velocity – Understanding how to calculate effective speed when two velocities are involved (swimming speed and river current).
Distance and Time Relationship – Applying the formula Time = Distance / Speed to find the time taken to cross the river.
