Physics Boat Crossing River With Current Question?
With the upstream: Velocity of stream + velocity of boat -5.0 m/s+7.5 m/s=2.5 m/s Given: Δx=500 m, v0=2.5 m/s, a=0 m/s xf=x0+vot+(1/2)(a)(t^2) 500m=0m+(2.5m/s)t+(1/2)(0)(t^2) 500 m=(2.5 m/s)(t) (500 m)/(2.5 m/s) = t 200s=t Down stream: Velocity of the river+velocity of boat 5.0 m/s+7.5 m/s=12.5 m/s xf=x0+vot+(1/2)(a)(t^2) 500m=0m+(12.5 m/s)t+(1/2)(0)(t^2) 500 m=(12.5 m/s)(t) (500 m)/(12.5 m/s) = t 40 s=t Time upstream+Time Downstream=Total time 200 s+40 s=240 s
Regents Physics question?
The boat is moving at 2m/s east relative to the water The water is moving 1.5m/s south relative to the ground. a) To find the velocity of the boat relative to the ground you have to add (2m/s east) + (1.5m/s south), by vector addition. This gives a speed (magnitude of boat's velocity) = sqrt(2^2 + 1.5^2) = 2.5m/s b) The the boat has to travel 30m with an eastward's velocity component of 1.5m/s. The southward 's component does not affect of the eastwards movement, as they are perpendicular. time = (distance to east) / (easterly speed) = 30/2 = 15s If you don't know how to add vectors, see link.
Help with a physics question?
The quickie way that only works for very convenient angles like this one: Note that 135 degrees = 90 degrees + 45 degrees. If the boat is pointed at a 45 degree angle upstream, then it's up river and cross river velocity components must be equal. So it is pushing upstream with a velocity of 8 km/hr which exactly balances the river pushing down stream, so the river must be pushing down stream at 8 km/hr. The general solution which will work for any angle: OK, this is a 2D vector problem. Break vectors in to their X (along river) and Y (across river) components: Vriver + Vboat = Vtotal Vriver = ( Vr, 0 ) { the quantity we're trying to find along the river, no velocity across the river } Vboat = ( Vb * cos(135), Vb * sin(135) ) Vtotal = ( 0, 8 km/hr ) { no net velocity down river, 8 km/hr directly across } Thus, for the X coordinate, we have: Vr + Vb * cos(135) = 0 for the Y coordinate, we have: 0 + Vb * sin(135) = 8 Substituting, Vb = 8/sin(135), we have: Vr + 8 * cos(135) / sin(135) = 0 Thus, Vr = - 8 * cos(135)/sin(135) = -8 * cot(135) = -8 * -1 = 8 km/hr
Tough Physics C question?
A child in danger of drowning in a river is being carried downstream by a current that has a speed of 2.70 km/h. The child is 0.600 km from shore and 0.800 km upstream of a boat landing when a rescue boat sets out. (a) If the boat proceeds at its maximum speed of 20.0 km/h relative to the water, what heading relative to the current should the pilot take? ° relative to the direction of the current (b) What angle does the boat velocity make with the current? ° relative to the direction of the current (c) How long does it take the boat to reach the child? s
Physics problem. A boat with its current cargo displaces 9.0 m^3 of water (fresh water)?
A boat displaces the equal amount of water weight. To find your answer, you need to find the weight of a cubic meter of water. A word of warning - The total volume of the ships hull is not the threshold to use for sinking. Prove me wrong - take a glass bowl and float it in the sink. Slowly add water to the bowl. Notice how the bowl will sink before it fills with water.
Science / Physics HW Question Help Please?
A boat crosses a river of width 104 m in which the current has a uniform speed of 0.945 m/s. The pilot maintains a bearing (i.e., the direction in which the boat points) perpendicular to the river and a throttle setting to give a constant speed of 1.79 m/s relative to the water. What is the magnitude of the speed of the boat relative to a stationary shore observer? Answer in units of m/s. Also, how far downstream from the initial position is the boat when it reaches the opposite shore? Answer in units of m.
Boat question. Physics help with formulas!?
Sketch a rightangled triangle with side 2.2 across the stream, 1.0 along the stream. The hypotenuse is the resultant velocity. Use Pythagoras' to find its magnitude, and tan θ = 2.2/1 to find the angle it makes with the direction of the current. (b) This is the simplest question of all: In 3.00s it has gone 3.00m downstream and 3.00*2.20 = 6.60m across. (Again, although you're not asked for it, Pythag would give you its distance from starting point, but you could get it just by multiplying 3.00 by the magnitude of resultant velocity.)
Motor boat physics question. velocity. displacement. etc.?
A motor boat traveling 4m/s, East encounters a current traveling 7 m/s North. 1. What is the resultant velocity of the motorboat? 2. If the width of the river is 80 meters wide then how much time does it take the boat to travel shore to shore? 3. What distance downstream does the boat reach the opposite shore? please show all work.
Physics-Boat Crossing a River?
A boat that can travel at 4.0km per hour in still water crosses a river with a current of 2.0km/h. At what angle must the boat be pointed upstream (that is relative to its actual path) to go straight across the river? The correct answer is 30 degrees but why? What i did was add the two vectors together and find the angle between them, to get 63 degrees (atan(4/2)). Then I subtracted 90-63, to get 27 degrees (the degrees relative to the actual path) But this isn't the right answer.