Boat Definition and 366 Threads

Question: A boat of mass m is traveling with the velocity v0. At t=0 the power is shut off. Assuming water resistance proportional to v^n, where n is a constant and v is the instantaneous velocity, find v as a function of the distance travelled. (Note that you need to consider the two cases)...

Homework Statement A boat takes 4.0 hr to travel 25 km down a river, then 5.0 hr to return. A. How fast is the river flowing? B. What is the velocity of the boat relative to the water flow? Homework Equations VAC=VAB+VBC The Attempt at a Solution For some reason I have trouble thinking in...

Hey everybody, I need help on a few word problems. The major problem I'm having is finding a formula to use. A bus is going to a football game and leaves at 4:00pm. It travels 20.91 miles to the game in 33 minutes. What is the bus' average speed in miles per hour? I'm completely clueless...

how much force does the water exert on a boat docked on a pier?

Homework Statement A boat is rowed with constant speed u starting from a point A on the bank of a river of width d , which flows with a constant speed nu . The boatman always points the boat at a point O on the other side of the bank opposite to A. Find the equation of the path r = f...

Hello, Im new to the forum, i joined to ask a question about a boat I've been obsessing about for awhile. My idea is an aluminum sail boat (27-40') that has its mast removed and replaced with say a 3-4kw vertical wind generator (350lb) i know that's a bit heavy but I am sure the wind forces are...

A guy at work gave me this drawing I have attached and asked me to find the pulley ratio. Do I need any other information such as rope lengths, pulley diameters, or load? I traded in my machine design book and don't remember exactly how to calculate the ratio. Is there anything else I can...

Homework Statement Consider a long straight river flowing north with parallel banks 40m apart. Let us use the function u(x) = 3 sin(\pix/40) to model the rate of water flow x units from the west bank.A boat proceeds at a constant speed of 5m/s from a point A on the west bank while maintaining...

You're floating in a boat in a pool with a 100 pound rock in the boat. You carefully measure the water level of the pool. Then you toss the rock out of the boat into the water. It sinks to the bottom. Does the water level of the pool go up, down or stay the same? Quantitative...

Homework Statement A dog weighing 5 kg is at the back of a boat of length 4m and weight 20 kg as shown below. Initially the dog is 8 m from shore. If the dog walks to the front of the boat, how far from shore will he be? [PLAIN]http://img72.imageshack.us/img72/6067/70134062.gif...

Homework Statement A boat starts a race at 3 m/s, accelerates uniformly for 10 seconds, then travels with constant velocity for 6 seconds. It then slows uniformly to rest in another 6 seconds. If the boat has traveled a total distance of 225m, find the maximum velocity. Homework Equations...

There's a project i have to do where i would be testing different kinds of propeller blades on the boat. Its just to test the effect of different blades so nothing has to be all high-tech. Apparently i know how i can make Propeller blades but i have no idea how to make the boat. I just need...

Homework Statement Lets image the following a boat has three people in it A has a mass of 120lb B has a mass of 180lb C has a mass of 160lb and the boat has a mass of 120lb also distance from person A to the front of the boat is 2 feet and distance from person A to person B is...

If you have a perfectly flat, rectangular raft and a perfectly flat, rectangular boat, which will displace more water? Or will the water displacement be the same. I remember that the water displacement is dependent on the shape of the floating object and the weight, but I can't remember exactly...

Homework Statement An aluminum boat is floating in a swimming pool. A hole opens up in the bottom of the boat, and it sinks to the bottom of the pool. Does the water level rise, fall, or stay the same?Homework Equations (Is the buoyancy equation applicable here?)The Attempt at a Solution...

Problem: a boat has to cross a river that is 1.5 km wide. There is a current of 5 km/h flowing parallel to the banks of the river. If the boat travels at 12 km/h relative to the water, what is the minimum time it will take the boat to cross the river? The fastest time will be if all of the...

Homework Statement A boat is moving at .5 m/s relative to the ground with a passenger riding inside of the boat. If the passenger jumps off of the front of the boat at a velocity of 4.0 m/s (relative to the boat), what is the total velocity of the passenger relative the the ground/water...

Homework Statement I'm getting fairly frustrated seeing as I've been working on this 'easy' problem for several hours yet still can't get the correct solution. The problem is as follows: A 180 lb- man and a 120-lb woman stand side by side at the same end of a 300-lb boat, ready to dive, each...

Homework Statement A: A boat capable of making 11.0 km/h in still water is used to cross a river flowing at speed of 3.0 km/h. At what angle (in o) must the boat be directed (from the perpendicular to the shore) so that its motion will be straight across the river? B: What is the...

Homework Statement A boat is 400 kg and cruising along with a constant speed of 4.0 m/s in a direction 30 degrees north of east. The boat suddenly begins to feel a force from the wind that is 45 degrees north of east and has a magnitude of 100N. After a 10 second period what is the velocity...

Homework Statement I have two questions but I need help with the second. 1. A boat can travel at 3.0ms-2 in still water and wishes to travel directly across a river with a current of 1.0ms-1. What direction upstream does the boat need to be steered. I got the answer - the boat goes at an 18...

Am considering the use of 6063 aluminum sq tube to repair/augment the structure of my river boat. Approx 3 yrs ago, I removed the 5 welded on chines that ran the length of the bottom of the boat ( they were mostly crushed & lost their strength ) and covered the bottom with 3/8" UHMW. This has...

i have made solar boat having 4V 400mA rating solar panel. when i put under sunlight there is no problem but i have to run it under helogen light so when i put it undet bulb then it gives me only 200mA current at 25 cm distance i can't decrease distance i m using 1381 solar engine using 5.5V/1F...

Hello everyone, When you go on a boat and use the paddle and displace water molecules you create low water pressure right? Then why does the boat move forward? I know water would flow from high to low but how can you specfically know that water would fly from high to low in forward direction...

Homework Statement A Boat at Dock A wants to go to Dock B Straight across. Docks are 100m Apart. Vh=4m/s A) If Vo1m=6m/s find the direction he must aim boat (theta) to go straight to dock B B)Find time it takes to get to dock B C)If he aims boat directly north where will he land on the...

This is a thought experiment that my friends and I (physics graduate students all) were pondering while we should have been doing Jackson homework. Consider a boat traveling at relativistic speeds. From the boat's frame, the water is contracted, and therefore is more dense. This would...

I want to shorten my boat trailer so that it will fit in my garage in the winter, It has to be able to be put back together for the summer. Trailer is built with 5" aluminum I-beams running down each side. My idea is to cut the two beams and splice back together with 4 pieces of aluminum channel...

Homework Statement a boat that can travel at 12.5 m/s on a lake goes 10.6 m/s when going straight up river (with respect to land) if the boat turns and heads (points) 22 degrees upstream from straight across the river. what is the boat's resultant velocity Homework Equations I don't...

Homework Statement Romeo (80.3 kg) entertains Juliet (58.0 kg) by playing his guitar from the rear of their boat at rest in still water, 2.73 m away from Juliet who is in the front of the boat. After the serenade, Juliet carefully moves to the rear of the boat (away from shore) to plant a kiss...

A ferryboat of mass M1 = 2.0 x 10^5 kilograms moves toward a docking bumper of mass M 2 that is attached to a shock absorber. Shown below is a speed v vs. time t graph of the ferryboat from the time it cuts off its engines to the time it first comes to rest after colliding with the bumper. At...

When cars turn they lean away from the turn as the torque from the centripetal force is balanced by the larger normal force on the tires on the outside of the turn. However, boats lean into their turns. So when a boat is turning left, it will lean to left. This doesn't make any sense to me...

Homework Statement A boat that can travel at 4.0 km/h in still water crosses a river with a current of 1.8 km/h. At what angle must the boat be pointed upstream to travel straight across the river? In other words, in what direction is the velocity of the boat relative to the water? 1...

URGENT : to find the path (function) of the boat pursuing another boat.. Homework Statement QUESTION : A boat A moves along the y-axis with constant speed 'V'. Find the path ( function f(x) ) of a second boat B which moves in the left half of the (x,y) plane with constant speed 'v' and...

Homework Statement http://img198.imageshack.us/img198/3834/relativeboatvelocity.jpg The note says "( Wind relative to boat is irrelevant! )" Why is it irrelevant?

Hi From this post you will deduce that one of my hobbies is sailing, I believe that applying a bit of science to the situation will improve my ability to make better tactical decisions on the spot. I have a GPS but am interested in getting a quick visual of boat speed related to the angle...

Homework Statement An empty boat floats in water with 10% of its volume submerged,and when it's loaded with 1200kg,the volume submerged will increase to 70% of the total volume. (1) Calculate the mass of the empty boat (2) If a leak develops and water starts to enter the boat which is...

Homework Statement A plane flies 2750 m[W] in 25s and then 5810m [S] in 67s a) What is the average speed of the plane? b) What is the average velocity of the plane? I tried doing it and I don't know if I'm right. My physics teacher can't explain anything for beans so could you please explain...

Can you make a wind turbine powered boat or cart that travels forwards directly into a headwind without storing energy at any time? Like this: http://www.treehugger.com/files/2007/02/windmill_sailbo.php It seems to me that it's a bit like making a cart that's geared in such a way as to...

Homework Statement A(n) 64 kg boat that is 8 m in length is initially 8.5 m from the pier. A 32 kg child stands at the end of the boat closest to the pier. The child then notices a turtle on a rock at the far end of the boat and proceeds to walk to the far end of the boat to observe the...

Can anyone tell me how much upward force a boat (say 24 feet x 8 feet, weighing 4000 lbs) exerts as it rises 1 foot on an incoming tide? My son asked me whether or not somone could hold the boat down as it tried to rise and I thought not but can't quite figure out how to quantify how hard it...

Boat A's position is given by the parametric equation x=3-t, y= 2t -4 where position is km and time is hours. Boat B's poisiton is given by x=4-3t, y= 3-2t a) find the initail position of each boat b) find the velocity vector of each both c) what is the angle between the paths of the boat...

Homework Statement A boat is traveling along a circular path having a radius of 20m. Determine the magnitude of the boat's acceleration when the speed is v=5m/s and the rate of increase in the speed is v'=2 m/s^2 Homework Equations a=(a(t)^2+a(n)^2)^1/2 The Attempt at a Solution...

Homework Statement Ocean waves traveling to the east at speed of 4 m/s. the distance between the crests is 20 m. With what frequency do the waves hit the front of a boat moving westward at a speed of 1 m/s? 2. The attempt at a solution Does the speed of the wave is added or subtracted from the...

Assume you have a can (representing a boat) with a hole in the bottom floating in a tank filled with water. The "boat" will start to sink. Now to my question.. My teacher told me that the speed of which water is runnig through the hole of the can is constant. But i can't seem to understand...

Homework Statement A woman and her husband simultaneously dive from a 120 kg raft that is initially at rest. The woman (60 kg) jumps from the boat with a horizontal speed of 1.9 m/s due south, while her husband (77 kg) jumps with a horizontal speed of 1.5 m/s due west. Calculate the...

An airboat with mass 4.38 102 kg, including passengers, has an engine that produces a net horizontal force of 8.08 102 N, after accounting for forces of resistance. a>how long does it take the airboat to reach a speed of 16.0 m/s? b>After reaching this speed, the pilot turns off the engine and...

Homework Statement Newspaper Boat- So I have been thinking about designing a newspaper boat out of pure entertainment. I want to build a boat out of shellack, tape, and newspaper, to maximize speed (to race people in swimming pools). considering i have some amount of these supplies, what...

Homework Statement a father and son went on a cruise that's 20 ft long. the dad observed the cruise swayed thru 22 complete oscillations in 38 s, and one wave crest pass per/oscillation. the son noticed that each crest required 13s to reach land and the wavelenght is twice the length of the...

Homework Statement Homework Equations p=mv XCM = (m1x1 + m2x2)/(m1 + m2) The Attempt at a Solution I'm really confused on this problem. I'm not sure if I should be using conservation of momentum, or what. Also do I have to compute the center of mass for the boat? Thanks

Homework Statement A boat moves 15.0 km across a lake in 30.0 min. What was the average speed of the boat in kilometers per hour? Homework Equations average speed: d/t The Attempt at a Solution ok since it is asking kilometers per hour that is the part tha confuses me. i mean i...