1.
How is the direction of a boat along with the stream called?
Correct Answer
A. Downstream
Explanation
When a boat moves in the same direction as the stream or current, it is called downstream. This means that the boat is moving with the flow of the water, which can make it easier for the boat to navigate and travel at a faster speed.
2.
How is the direction of a boat against the stream called?
Correct Answer
B. Upstream
Explanation
The direction of a boat against the stream is called upstream. This term refers to the movement of a boat or any other object in the opposite direction of the current or flow of the water. It implies that the boat is moving against the natural force of the stream, which requires more effort and power to make progress.
3.
What's the formula for the speed of water?
Correct Answer
B. V km/hr
Explanation
The formula for the speed of water is represented by the variable "V" in kilometers per hour.
4.
What's the formula for the speed of the boat in calm water?
Correct Answer
A. U km/hr
Explanation
The formula for the speed of the boat in calm water is represented by U km/hr.
5.
What's the formula for speed downstream?
Correct Answer
C. U km/hr
Explanation
The formula for speed downstream is U km/hr.
6.
What's the formula for speed upstream?
Correct Answer
A. (U-V) km/hr
Explanation
The formula for speed upstream is (U-V) km/hr. This formula represents the difference between the speed of the boat or object in still water (U) and the speed of the current or stream (V). When the current is against the direction of the boat, the effective speed is reduced by the speed of the current, hence the subtraction of V from U in the formula.
7.
What's the formula for the speed in still water?
Correct Answer
B. 1/2 (x+y) km/hr
Explanation
The formula for the speed in still water is 1/2 (x+y) km/hr. This formula represents the average speed of a boat in still water, where x represents the speed of the boat in upstream (against the current) and y represents the speed of the boat in downstream (with the current). The average speed is calculated by taking the average of the speeds in both directions, which is why it is divided by 2.
8.
A boatman covers a distance of 24 km against the water current and 36 km in direction of the water current. If it takes each time 6 hours, then find the speed of current.
Correct Answer
A. 1 km/hr
Explanation
The boatman covers a distance of 24 km against the water current, which means he is moving against the current. The time taken to cover this distance is 6 hours. Similarly, he covers a distance of 36 km in the direction of the water current, which means he is moving with the current. Again, the time taken is 6 hours. Since the time taken is the same in both cases, it implies that the speed of the boat is the same in both cases. Therefore, the speed of the current must be 0 km/hr.
9.
A boat in one hour covers about 12 km along with stream and 6 km against the stream. Find the speed of boat in still water.
Correct Answer
C. 9 km/hr
Explanation
The speed of the boat in still water can be found by taking the average of the speed of the boat along with the stream and against the stream. In this case, the boat covers 12 km along with the stream in one hour and 6 km against the stream in one hour. Taking the average of these two speeds gives us 9 km/hr, which is the speed of the boat in still water.
10.
A fisherman sailing upstream and covers 16 km and sailing downstream and covers 25 km taking 6 hours each time. Find the velocity of water current.
Correct Answer
A. 1 km/hr
Explanation
The fisherman's speed when sailing upstream can be represented as the speed of the boat minus the velocity of the water current, while the speed when sailing downstream can be represented as the speed of the boat plus the velocity of the water current. Let's assume the velocity of the water current is x km/hr. From the given information, we can set up the following equations: 16 = (boat speed - x) * 6 and 25 = (boat speed + x) * 6. Solving these equations, we find that the boat speed is 10 km/hr and the velocity of the water current is 1 km/hr.