What is relative velocity formula?

What is relative velocity formula?

The relative velocity is the velocity that the body A would appear to an observer on the body B and vice versa. Mathematically speaking the relative velocity is the vector difference between the velocities of two bodies. Relative velocity = velocity of the body A – velocity of the body B. The equation is: vAB = vA – vB.

How can you measure the speed of a boat moving in water?

Pitometer logs (also known as pit logs) are devices used to measure a ship’s speed relative to the water. They are used on both surface ships and submarines. Data from the pitometer log is usually fed directly into the ship’s navigation system.

How do boats calculate speed?

The speedometer on a boat is called a pitometer and it measures the speed of the boat as compared to the water speed. A tube goes through the hull of the boat and into the water. There are two openings in the tube. One measures the water speed as it moves through the tube, and the other measures the water pressure.

When a boat tends to cross a river in shortest time?

(i) Shortest time : To cross the river by the shortest time, he has to be rowed perpendicular to the river. As a result of the river velocity the person will reach a point say C from A. (drawn the current).

How does a Pitometer work?

A speedometer on a boat works by using a pitometer. The pitometer works by comparing how fast your boat is going against the speed of the water you’re travelling on. This works by measuring the speed of water coming into a tube compared to air pressure to give an estimated speed figure.

How does a speedometer work on a pontoon boat?

Rather than measuring your speed on the water, these speedos work by showing you how fast you’re moving through space from one destination to the next. Just as they work on land a GPS speedo can provide you with instant updates on your speed from a digital gauge on your dashboard.

How does a boat GPS speedometer work?

A pitot tube speedometer relies on tubes under the boat to help gauge speed. The tube goes through the boat’s hull and down below into the water. There are two holes in the tube. As you travel in the boat, water enters the tube through one hole.

How do you hook up a speedometer on a boat?

The hole should be well above the waterline and should be angled downward about 45 degrees. Insert the pressure tube into the hole and connect it to the pitot. Secure the pressure tube in place using cable clips and sealant. The other end of the pressure tube should be connected to the speedometer display.

Why does my speedometer not work on my boat?

The usual problems are a blocked orifice (little hole in the arm), a blocked vinyl tube and a disconnected, broken, cracked or holed vinyl tube. The easy way to check if to remove the tube from the pitot tube mount and blow into the vinyl hose. If the speedo moves, it’s likely the pitot is plugged.

How accurate is GPS speed on a boat?

First, most speedos are not very accurate, but GPS is very accurate at measuring speed over ground. Second, even with an accurate speedo, there can be tidal currents that impact actual speed over ground, and actual speed over water.

What makes your speedometer stop working?

The most common causes of a speedometer that stopped working include are a faulty speed sensor, a broken gear on the speedometer, damaged wiring, or a faulty engine control unit.

What is a pitot sensor Mercury?

posted 09-26-2005 10:47 PM ET (US) The pitot tube is the speedometer for the engine management. computer. It works by measuring the water pressure against the. hole(s).

How do you check RPM gauge on a boat?

Start the motor, turn on the shop tachometer meter and run the motor up to 1,000 rpm on the shop tachometer. Take note of and compare this reading to your boat’s tachometer. Check the outboard’s charging system if no signal is detected.

How accurate are tachometers?

This digital tachometer produces readings as fine as . 01 RPM for devices spinning below 100 RPM, . 1 RPM for speeds between 100-1000 RPM, and 1 RPM for speeds between 1000 and 99,999 RPM. And this device is accurate to 0.02%.

How do I know if my tachometer is accurate?

You can put a piece of reflective tape on the engine’s flywheel to get a general idea of the accuracy of the tach. 1000, 2000 rpms should be close. You can check several rpms and make a table to see if it’s accurate throughout the rpm range or if the accuracy changes at different rpms.

How do you check a tachometer?

Set the meter to AC voltage. Connect the negative Meter lead to a good chassis ground in the vehicle and the positive lead to the suspected tachometer wire. Start the vehicle and wait for it to idle down to normal idle speed. At this point the meter should be displaying a fairly constant AC voltage.

Is there a fuse for the tachometer?

Check the Fuses: If you look for the fuse box in your car, find the fuse for the tachometer. If it has blown this could be the source of your problem. Check Wire Connections: If you look at the parts inside the tachometer, you will be able to see whether the parts are damaged, melted, or burnt.

Where is RPM sensor located?

The Engine Speed (RPM) Sensor is located in the front of the transmission bellhousing on the driver-s side. (shown without the sensor). The Engine Speed (RPM) Sensor is located on the front of the engine block, lower left, near the transmission flange.

What makes a tachometer jump?

What causes tachometer to fluctuate? A blown fuse is a potential problem with the tachometer. Bad wiring can also be the cause of a malfunctioning tachometer. If you are getting erratic readings, this can be a sign of bad wiring.

Is it normal for my rpm going up and down?

Hi There, It sounds like you may have a dirty or failing idle air control valve causing your engine idle to fluctuate. When this happens, the job of the idle air control valve is to bring this deceleration down to a slow and smooth idle rather than suddenly cutting off the fuel supply causing the motor to die.

What causes the RPM needle to jump back and forth?

If the “RPM gauge”–actually the tachometer–is jumping all over the place, that could indicate a problem with the engine or with the transmission. If the transmission is not slipping, then the problem probably lies in the engine.

Why do my RPMs jump when accelerating?

If your RPM fluctuates while accelerating, it could be because your spark plugs have gone bad on you. Worn-out spark plugs can cause misfires to occur within your engine, and those misfires can lead to your engine vibrating a whole lot. Those vibrations can lead to the RPM in your engine going haywire on you.

How do you fix a car jerking when accelerating?

My Car Jerks When Accelerating: How Much Will It Cost to Fix?

1. Replace spark plugs: Between $50 and $150.
2. Clean fuel injectors: Between $50 and $100.
3. Replace air intake system: Between $150 and $500.
4. Replace mass airflow sensor: Between $275 and $400.
5. Replace accelerator cable: Between $100 and $375.

What causes a car to stutter on acceleration?

An acceleration problem is usually the result of insufficient fuel, air, or spark during the combustion process. Worn-out spark plugs or the electrical cables attached to them are one of the most common causes of cars stuttering.