A 30 meter wide canal is flowing at the rate of 20 m/min. A boy can swim at the rate of 25 m/min in still water. The time taken by him to cross the canal perpendicular to

Question

A 30 meter wide canal is flowing at the rate of 20 m/min. A boy can swim at the rate of 25 m/min in still water. The time taken by him to cross the canal perpendicular to

the flow is

Answer 1

To have a velocity directly across relative to land, the boy must aim upstream relative to the water.

25 m/min is the vector sum of 20 m/min along the river flow and 15 m/min straight across, because
25^2 = 15^2 + 20^2

The time required to swim 30 m across is
t = 30/ 15 = 2 minutes.

Answer 2

Thanks💓

Answer 3

To cross the canal perpendicular to the flow, the boy needs to swim across the width of the canal.

Given:
Width of the canal = 30 meters
Boy's swimming speed = 25 m/min

To find the time taken by the boy to cross the canal, we can use the formula:
Time = Distance / Speed

Since the distance to be covered is the width of the canal, the time taken by the boy to cross the canal is:

Time = Width / Speed
Time = 30 meters / 25 m/min

Calculating this, the time taken by the boy to cross the canal perpendicular to the flow is:

Time = 1.2 minutes or 1 minute and 12 seconds.

Answer 4

To find the time taken by the boy to cross the canal perpendicularly to the flow, we need to consider the relative motion of the boy and the canal.

Let's break down the motion into components:

1. The velocity of the canal flowing in the horizontal direction is 20 m/min.

2. The velocity of the boy swimming in still water is 25 m/min.

Now, let's consider the boy swimming perpendicular to the flow:

The velocity of the boy is the resultant of his velocity in still water and the velocity of the canal.

By using vector addition, we can find the magnitude and direction of the resultant velocity.

Since the boy is swimming directly perpendicular to the flow, both velocities are perpendicular, resulting in a right-angled triangle.

Using the Pythagorean theorem, we can calculate the magnitude of the resultant velocity:

Resultant Velocity^2 = (Velocity of the Canal)^2 + (Velocity of the Boy)^2

Resultant Velocity^2 = (20 m/min)^2 + (25 m/min)^2

Resultant Velocity^2 = 400 + 625

Resultant Velocity^2 = 1025

Resultant Velocity = √1025 = 32.02 m/min (approximately)

Now, we can calculate the time taken by the boy to cross the canal:

Time = Distance / Resultant Velocity

Distance = 30 meters (given)

Time = 30 meters / 32.02 m/min

Time = 0.936 minutes (approximately)

Therefore, it will take the boy approximately 0.936 minutes to cross the canal perpendicularly to the flow.