What is Braking: Definition and 197 Discussions

The two most unscientific words in Star Trek are probably "full stop". :wink: The Impulse Drive is described in the Voyager Technical Manual as 0.25 c (25% of the speed of light). Whatever g forces are required to "immediately" come to a halt from that speed - it's certainly way beyond what the...

Start velocity is 100 km/h, at 1.5g for 0.5 seconds the end velocity will be 73,52 km/h. So the energy can be calculated if the mass is present, but it is not given. Is there a way to calculate the regenerated energy with the given information?

Let's imagine we have a ship heading towards our planet. It fires forward thrusters to brake. The ship is long way away. Because the ship decelerates, (slows down towards us) would we see particles from its exhaust doppler shifted blue or red? On the one hand the gas is flying towards Earth, so...

When a magnet moves near a non-magnetic conductor such as copper and aluminium, it experiences a dissipative force called magnetic braking force. I am rather confused by the following explanation of magnetic braking force: The non-magnetic conductor here is the aluminium 'wall' seen on the...

Hello! So what I've tried to tackle this problem is derive the equation,set it equal to zero,find a value for v and than put it in the second derivation.So when I derive this I get $$ \frac{v^2+9-v *(2v)}{v^4+8v^2+16)} $$ Now if i set that equal 0 and try to find a value for v I get this. ##...

Hi guys I'm a truck driver. Not sure if I'm posting in the right place so i apologise. Iv'e been on a course today about trucks. The course leader was talking about forces. A trucks force forwards can be 0.8. Is this true?

I'm a little confused about this question because I think the braking deceleration probably takes into account the braking system of the vehicle as well as the power of the motor. I don't understand how a car could actually brake without the "friction between the mechanical components of the...

I tried using equations listed above to get the answer, but I get stuck with a and Vi. What am I doing wrong? The answer is 6.7 seconds.

I am trying to understand what happens in the engine (especially gasoline vehicles) during coasting (in drive mode) and engine braking. It looks like both mechanisms shut off the fuel injectors. Then how is the former (coasting in drive mode) able to use the momentum while the latter (engine...

I want to know how to calculate the braking force acting on a magnet falling through a copper tube. The setup can be seen in this video (YouTube, @ 1:49 - 3:12): Copper's Surprising Reaction to Strong Magnets. Note that it's not a copper tube in the video but a plastic tube surrounded by a...

I ride gravel bikes on steep mountain roads and on the way down I have to ride the brakes pretty hard. I want to minimize brake heat so I have always thought that keeping the bike's velocity lower on average by applying the brakes more often will reduce the amount of energy the brakes will have...

Lately, I've been reading about the electronics required for driving motors and naturally that transitioned into braking. I think I have a decent grasp on resistive braking but I do not fully grasp regenerative braking. This plus googling gaps in my knowledge have been my primary sources...

If you let a magnet free-fall down a copper or aluminum tube, the induced magnetic field in the surrounding conductive medium imposes a braking effect on the magnet, reducing its speed (explained by Lenz’s law). The earth, being a large magnet, is essentially free-falling around the sun. The...

The truck stops in a shorter distance if the crate slides but why is this the case considering that friction on the crate does positive work on the truck, since it points left for the crate but right for the truck thereby opposing the braking force? I understand why using the equation 1/2mv^2 =...

Hello everyone ! I've got a problem in engineering class with a braking system (picture linked). In the first part I calculated the friction force $$ \vec{B} $$ with components : T (following y axis) : 2073.6N N (following x axis) : 5760N. For the first question I struggle a lot because I...

i have been stuck on this question from my assignment, i have tried solving it in many ways, but apparently i am either bad at this or i just don't understand the question haha. * As a prudent engineer, the main shaft is now subjected to loading condition when only brake is applied. Show with...

How strong does a permanent magnet/electromagnet need to be in order to see the effects of magnetic braking on a flat metal pendulum?

1. For the car to apply brakes, we have ##v^2=2ar⇒a=\frac{v^2}{2r}=μg\;\;[ma=μmg]⇒v=\sqrt{2μgr} ## 2. For the car to go in a circle ##\frac{mv^2}{r}=μmg\Rightarrow v=\sqrt{\mu gr}##. We find from above that the maximum velocity ##v## possible to avoid a collision is ##\sqrt{2}## times as much...

Reading recently a Russian MOD aerospace journal, i stumbled upon (pretty unrealistic) scheme to hard-land payloads (metal ingots) on moon. It involve catching 1.7 km/s slugs with the pipe filled by regolith or water, and even more hardcore option of digging up the payloads embedded in the...

Homework Statement: Finding the braking torque applied on a moving disk as a result of the Eddy Currents Homework Equations: $$F = \sigma v V B^2$$ So right, Basically my problem is how to find the torque exerted by an eddy current braking setup. My setup consists of a disk rotating on an...

Summary: How do you determine the armature current during the braking time? For a simple permanent magnet DC motor with a known resistance and inductance in series with the armature, I would like to know how to determine the armature current if there was an electronic motor drive controlling...

Step 1. Integrate the function --> it comes out to -1.8t3+t2-8t+c Step 2. Figure out the integration constant --> I know that the velocity of the car is 30m/s at t=0s so making 30m/s = -1.8(0s)3+(0s)2-8(0s)+C it would seem that C is 30m/s Step 3. Calculate velocity at 4s --> V(4s)=...

(The weight scale = 10 kg). After initial force, now the mass is lowering down at constant speed of 1 m/s. The motor with pulley's radius of 1 meter is exerted 100 Newton m to keep constant V. The motor speed is about 9.55 rpm. * All other weights, inertia and frictions of the system is...

I debated with a friend tonight, and I need some unbiased input. We were talking with a 3rd party that states that they only have one *working* brake caliper, of four. Assertion #1. (Basic four wheeled vehicle) 3rd party also states that there is no correction in steering needed, when...

I'm working on a project and came across electromagnetic braking recently and I'm really curious to know if it's really feasible. The project in brief is a vehicle on a monorail at speeds of +600km/hr needs to be stopped. The monorail is made of an alloy of aluminium. I have no background in...

So I'm interested in adding a bank of capacitors to help reduce the initial load on my batteries when accelerating from a stop but my current set up uses regenerative braking. My electrinics are this order, Motors, VESC, BMS, 10s5p Li-ion pack. If I add capacitors between the bms and vesc to...

as homework, I have to do the following exercise: Bremstrahlung emission : We are interested in ionized plasma of density ##n##, at temperature ##T## with ions of charge number ##Z##. 1. Explain the physical origin of bremstrahlung radiation 2. Represent the expected spectra (shape and...

Homework Statement :[/B] A ball rolls onto the path of your car as you drive down a quiet neighborhood street. To avoid hitting the child that runs to retrieve the ball, you apply your brakes for 1.06 s. The car slows down from 14.5î + 4.50 m/s to 8.25î + 3.50 m/s. How far did the car move...

Got a question for you mechanics enthusiasts out there. Here https://i.imgur.com/Px0Hakg.jpg from what I gather is a basic force diagram depicting a car accelerating along a straight road, Dr represents the driving force of the engine, Fr the friction acting on the tyres against the direction of...

Homework Statement A motorist is traveling at 10m/s in a car whose maximum deceleration rate is 5.0 m/s^2 The effective reaction time between seeing a hazard and starting to brake is 0.5s Calculate the thinking distance for the drover ar this speed (ie the distance traveled during his...

Homework Statement A train 400 m long is moving on a straight track with a speed of 21.6m/s. The engineer applies the brakes at a crossing, and later the last car passes the crossing with a speed of 5.0m/s. Assuming constant acceleration, determine how long the train blocked the crossing...

Homework Statement To stop a car, first you require a certain reaction time to begin braking; then the car slows down under constant breaking decelaration. Suppose that the total distance moved by the car during these two phases is 56.7 m when its initial speed was 80.5 km/h and 24.4 m when its...

Hello everyone ! I'm working on my highway code and my book give me the approximate formula and the real formula of the braking distance. Here's the real formula according to the book : $$ Bd = \frac{V^2}{254 \times f} $$ With : V : the velocity f : the adherence coefficient. But I have on...

Hi, I've seen many videos of neodymium magnets sliding slowly down an inclined copper plate, or slowly down a copper tube - due to eddy current braking,but never the other way around. My question is; will a copper disc sliding down an inclined magnetic plate, or down a magnetic tube act in the...

When the driver applies brakes its velocity starts decreasing and direction of acceleration will be same to the direction of velocity. Is this statement True of False? Please explain the true concept of this scenario. As far as I understand is that Velocity will start decreasing. But I am...

Hi All, The ECU on my motor bike allows you to select different amounts of engine braking in it's various riding modes. I imagine that the ECU just opens up the throttle bodies a little so that at closed throttle the engine still delivers a bit of torque. Doing this will increase the idle speed...

Hello! I'm currently working on a project that will utilize the phenomena of eddy currents to apply a braking force to a rotating disk. Some background on this project: My team was tasked to create a physical therapy training device to train patients in wheelchair propulsion at resistances lower...

Hello, I'm currently working on the design of an e-caliper and I need to this effect to determine the linear force at which the pads have to be pressed against the disc to slow down a car swiftly. The result of my calculations is that the pad of a single front brake has to be pushed with a...

Hello! How can we identify that a car is braking, just by accessing its wheels? I think dynos work like that? Ie they can tell if the torque is negative or positive by touching the spinning wheel? Any hint?

Hi So I am busy studying rotational motion and there's an example in the book where they explain that when a car brakes the force of friction acts as a torque force which explains why a car lifts up at the back when braking. Because the car does no rotational motion they say the net torque is...

When a charge is accelerated it brakes because it emits radiation. If a carge is accelerated with costant acceleration and the traiectory is a line what is the frequency of the emitted radiation? (I think 0Hz but i am not sure)

I understand intuitively that an automobile is set in motion because the wheels apply a force on the road in a backwards direction. Using Newton's 3rd law, the car gets propelled because the road applies a reaction force in the opposite direction. Before starting to ask my full question, I...

Adaptive/active/radar cruise control (Update: It is not adaptive cruise control. It is automatic emergency braking) works only at or below 50 miles (per hour) in some high end cars like range rover, and even below that in other cars. Does anyone know why?Thanks a lot

Homework Statement A bicycle rider is riding at a constant speed of v(b) and at t=0 is 17m behind the car. The cyclist reaches the car when the car just comes to rest. The car is moving with an acceleration:for 0<t<t(1) a(c)=0 for t(1)<t<t(2) a(c)= -c(t-t(1)) where its initial component...

Homework Statement A truck of mass 1.5 tonnes (1500 kg) is moving at a speed of 36 km/h down a hill of slope 1 in 6. The driver applies the breaks and the truck comes to rest after 2 seconds. Find the breaking force, which is assumed to be constant, ignoring any other resistant forces...

Magnetic braking is a theory explains the loss of stellar angular momentum and is used extensively to describe the given rotation stars. However, on a smaller and more directly observable level, when we consider Jupiter's rapid rotation rate of less than ten hours and its accompanying powerful...

When trying to abruptly stop a motorcycle that is in motion, can engine braking actually have a negative effect on the rate of deceleration? Scenario: a motorcycle is traveling down a straight highway at 100mph in 6th gear and needs to perform an emergency stop. The weather is clear and road...

I recently read about zero sequence braking of induction motor. In zero sequence braking of induction motor, the stator phases are connected in series and a single phase ac supply is connected across the series combination. Thus, the currents in all three phases are co-phasal, which are called...

When driving on snow and ice does engine braking (by downshifting) provide more traction than applying brakes in a slow and controlled manner?

Homework Statement So here is the Problem: A big truck (m=50t) is going at 100km/h. Now the truck can't brake anymore and Superman comes to aid. He (has a mass of m=100kg) tries to stop the truck while he is wearing shoes with a rubber-texture and a friction coefficient of µ = 0.8. Assume that...