A boat crosses a river 1.5km wide in 15mins. If the river flows at 2km/hr calculate the velocity of the boat.
To calculate the velocity of the boat, we can use the concept of relative velocity.
First, we need to determine the time it took for the boat to cross the river. The boat crosses a distance of 1.5 km in 15 minutes. We know that time = distance / speed. Therefore, the speed at which the boat crosses the river is:
Speed of boat crossing river = distance / time
= 1.5 km / 15 minutes
= 0.1 km/min
Next, we need to account for the speed of the river. The river flows at a speed of 2 km/hr. In order to calculate the relative velocity, we need to convert the speed of the river into the same units as the speed of the boat, which is km/min. We know that 1 hour = 60 minutes. Therefore, the speed of the river is:
Speed of river = 2 km/hr * (1 hr / 60 min)
= 0.0333 km/min
Now, we can calculate the velocity of the boat by considering the effect of the river's flow. The velocity of the boat is the difference between the boat's speed and the river's speed. Therefore:
Velocity of the boat = Speed of boat crossing river - Speed of river
= 0.1 km/min - 0.0333 km/min
= 0.0667 km/min
So, the velocity of the boat, considering the effect of the river's flow, is 0.0667 km/min.
boat speed=6km/hr (in calm water0
velociyt= sqrt(6^2 + 2^2)