Answer: Due to speed of water flow in river, a person either swimming or floating stationary in the river experiences a pushing force along the flow direction.
Why does the boat not move in still water?
The boat cannot cross the river to an exactly opposite point. In this case, the drift is minimum if →vb=→vb/w+→vw v → b = v → b / w + v → w is perpendicular to →vb/w v → b / w . The angle made by →vb/w v → b / w with →vw v → w is given by θ=cos−1−vb/wvw=cos−1−12=150degree.
Why is it difficult to cross fast flowing river using a boat?
The velocity vBW of the boat relative to the water is the velocity measured by an observer who, for instance, is floating on an inner tube and drifting downstream with the current. When the engine is turned off, the boat also drifts downstream with the current, and vBW is zero.
How do you solve Rain Man problems?
It is the force of friction between the surface of water and the boat that brings the boat to rest once we stop rowing. Was this answer helpful?
What is the resultant velocity of the boat?
The river moves downstream parallel to the banks of the river. As such, there is no way that the current is capable of assisting a boat in crossing a river.
How fast is the river flowing physics?
When he crosses a river with shortest time one component of boat velocity is opposite to velocity of water and other component is perpendicular to velocity of water.
What is drift in river problems?
The resultant velocity will this stretch from the tail of the boat velocity (if drawn first) to the arrowhead of the river velocity. This resultant velocity will be a vector directed south and east (or south and west, depending on the direction of the river velocity.)
What is the formula for minimum drift?
The speed of a river varies from close to 0 m/s to 3.1 m/s (7 mph). Factors that affect the speed of a river include the slope gradient, the roughness of the channel, and tides. Rivers tend to flow from a higher elevation to a lower elevation.
What is the motion of boat?
to find minimum D, we differentiate and then equate to 0 dDdt=0ut−vsin(x)t=D. If we have the velocity of the boat and the velocity of the river, then we can find the angle for which drift is minimum for that particular velocity of boat using the above relation.
How can you make the boat go faster?
- 3 Ways to Make a Boat Faster. Reduce weight.
- Reduce Weight. Reducing weight is like finding free horsepower, and many boat owners are surprised how much weight they can leave on the dock.
- Don’t Over-Trim.
- Change Your Propeller.
How do we calculate the acceleration of speed boat?
Multiply the acceleration by the time the object is being accelerated. For example, if an object falls for 3 seconds, multiply 3 by 9.8 meters per second squared, which is the acceleration from gravity. The resultant velocity in this case is 29.4 meters per second.
How can you move the boat in the still water answer?
At first glance, the ocean may appear flat, but it is anything but. A closer view offers a better look at the wind, currents, and wave action that influence how a ship moves in six degrees of motion: heave, sway, surge, roll, pitch, and yaw.
How can you move the boat in the still water?
Acceleration (a) is the change in velocity (Δv) over the change in time (Δt), represented by the equation a = Δv/Δt. This allows you to measure how fast velocity changes in meters per second squared (m/s^2).
Why does a boat comes to rest?
No external force acts on the ‘man+boat’ system when the man walks on the boat in still water, so the center of mass of the system remains at rest. In order to do so, the boat move away from the shore when the man walks towards the shore.
How do you cross the river in the shortest time?
By pushing the water, boatman applies a force on water in backward direction. In turn, water applies the same amount of force in forward direction, moving the boat ahead.
What direction should the boat be aimed to get to the other side of the river in the least amount of time?
It is the force of friction between the surface of the ball and the ground that brings the moving ball to rest. Similarly, friction between water and the boat brings it to a stop once you stop rowing.
What two quantities are needed to calculate the distance the boat travels downstream?
To cross the river in shortest distance, a swimmer should swim making angle theta with the upstream. What is the ratio of the time taken to swim across in the shortest time to that in swimming across over shortest distance.
What is sent across a river with a velocity of 8 km per hour if the resultant velocity of the boat is 10 Kilometre per hour then velocity of the river is?
Which direction should the boat point in order to reach the other side of the river in the least amount of time? flow of the river and take the most direct path across the stream. It will be the shortest distance and therefore the shortest amount of time.
What is sent across a river with a velocity of 8 km per hour if the resultant velocity of boat is 10 km per hour then velocity of the river is?
To calculate the distance the boat travels downstream, you need the time required for the boat to cross the river AND the speed of the river (current). 7.
How do you solve relative velocity problems?
Where is velocity highest in a river?
= √(10)2−(8)2=6 km/hr.
What affects the velocity of a river?
Answer: The velocity of river is 6 km/h.
Why do rivers move so fast?
1. Toward the middle of a river, water tends to flow fastest; toward the margins of the river it tends to flow slowest. 2. In a meandering river, water will tend to flow fastest along the outside bend of a meander, and slowest on the inside bend.
How do I fix downstream upstream problems?
- Upstream = (u−v) km/hr, where “u” is the speed of the boat in still water and “v” is the speed of the stream.
- Downstream = (u+v)Km/hr, where “u” is the speed of the boat in still water and “v” is the speed of the stream.
- Speed of Boat in Still Water = ½ (Downstream Speed + Upstream Speed)
What is the velocity of still water?
The velocity of a river is determined by many factors, including the shape of its channel, the gradient of the slope that the river moves along, the volume of water that the river carries and the amount of friction caused by rough edges within the riverbed.