A boat is ravelling in a river with a current of 3 km/hr. The boat is capable of travelling at 10 km/hr in still water. How long will it take the boat to travel 7km upstream
The boat velocity relative to land, going upstream, is 10 - 3 = 7 km/h
Time to travel 7 km
= 7 km/(7 km/h)
= 1 hour
To find out how long it will take for the boat to travel 7 km upstream, we need to consider the effect of the current.
When the boat is traveling upstream, it moves against the current, which slows it down. The actual speed of the boat when going upstream is the difference between its speed in still water and the speed of the current.
In this case, the speed of the boat in still water is 10 km/hr, and the current is 3 km/hr. So, the speed of the boat against the current is 10 km/hr - 3 km/hr = 7 km/hr.
Now, to calculate the time it takes to travel a certain distance, we can use the formula: Time = Distance / Speed.
Plugging in the values, we get: Time = 7 km / 7 km/hr = 1 hour.
Therefore, it will take the boat 1 hour to travel 7 km upstream.