Deceleration Definition and 226 Threads

Homework Statement A spacecraft with a mass of 9100kg (incl fuel) traveling at 8 m/s Rockets fire for 10 seconds burning 100kg of fuel slowing the spacecraft to 0.03 m/s What is the force the rockets provided during the 10 seconds? Homework Equations acceleration = ∆v/t F = m x a[/B]...

Homework Statement A man bungee jumps off a cliff and free falls for 3 seconds. The bungee cord stops the jumper in 5 seconds. How far did the man fall in total?Homework Equations X = V0t + 1/2at2 The Attempt at a Solution Xf = X1 + X2 X1 = V1it1 + 1/2a1t12 X1 = 0 * 3 + 1/2 * -9.8 * 32 X1 =...

Homework Statement I have a missile in space, and I want to rotate it by using thrusters - eight of them - two on every of four sides as force is applied pendicular - left, right, up and down - both on front and end of missile. Now I have angle to target, I know which thrusters should I turn on...

Homework Statement The engineer of a passenger train traveling at vP sights a freight train whose caboose is distance D ahead on the same track. The freight train is traveling at vF in the same direction as the passenger train. The engineer of the passenger train immediately applies the brakes...

Homework Statement A car with mass 1000kg moves with velocity 50 km/hour. The system of deceleration in a car is based on the principle of "force match" that is applied on each of four wheels with a force of 210 N and the ray of the wheel is 0.3m. Find for how much time, the car with stop and...

So this is about a modelling project I'm doing. If you have an object that was being towed in water and the towing force is suddenly removed. There is a force F=1/2(density of fluid)(C constant)(A)V^2 that acts on the object. I am trying to find the distance X it will take for the object to...

Homework Statement There are two train stations, 2.5km (2500m) apart, therefore an ordinary suburban train cannot reach its max v between the two station. They try to minimise time taken by accelerating at a constant rate of 0.1ms-2 for time t1 and decelerate at 0.5ms-2 for time t2. Find the...

1. A baseball is traveling at +18 m/s and is caught by a player. The ball is brought to rest in 0.5 s. What is the acceleration of the ball?Homework Equations Maybe vf=vi+ at ?The Attempt at a Solution This is under a Horizontal Projectiles worksheet by the way...I'm not sure what to do on this...

Hello everybody, I am trying to calculate the maximum velocity(x) an object reaches between two point. The object accelerates from point A to a certain velocity(x) and then decelerates to point B. The acceleration and deceleration are known but are different. The distance from point A to point...

Hi guys, I'm new to this site so forgive me if I'm unfamiliar with any etiquette unique to here. We did a practical exercise the other day in class in which we accelerated a bogey to a certain RPM and then released it to accelerate up a ramp. We were then given a sheet of the measurements I have...

Homework Statement What net force would be necessary to stop an automobile of mass 1000kg traveling initially at a speed of 15m/s in a distance equal to the diameter of a dime, which is 1.8cm ? Homework EquationsThe Attempt at a Solution The force required to stop the car is given by F =...

Homework Statement The engineer of a passenger train traveling at 25.0 m/s sights a freight train whose caboose is 200 m ahead on the same track. The freight train is traveling at 15.0 m/s in the same direction as the passenger train. The engineer of the passenger train immediately applies...

Homework Statement A person can just survive a full-body collision (either to the front, back, or side) which results in a deceleration that is up about 100 g's. (One g is 9.8 m/s/s). At greater deceleration fatal brain damage will likely occur. If a 66.4 kg man falls of a cliff of height 37.8...

I am programming an addon for a space game/simulation (Kerbal Space Program) and I am looking for some help with a bit of physics. The part I need a little help with is related to attitude control. If the ship is rotating, is there a mathematical way to calculate when it needs to begin to...

Homework Statement Give q(t) the deceleration parameter, as a function of: \Omega_{\Lambda}, the cosmological constant density, and \bar{a}(t) = \frac{a(t)}{a(t_{0})}= 1+ H_{0} (t-t_{0}) - \frac{1}{2} q_{0} H_{0}^{2} (t-t_{0})^{2} where a's the scale factors have already defined τ =...

Hi Everyone. I have a question for you all that is most definitely not homework - Its over 20 years since I was at school and sadly I can't remember very much of what our maths teacher told us... hence the reason I'm here! I work for a company that does off-road vehicle modifications...

Homework Statement "A car is approaching traffic lights. The car is traveling with speed 10ms-1. The driver applies the brakes to the car and the car comes to rest with constant deceleration in 16s. Modelling the car as a particle, find the deceleration of the car." Homework Equations v...

Homework Statement Given $$\frac{d^2s}{dt^2}=-Ae^{s/B}\biggl(\frac{ds}{dt}\biggr)^2$$ Show that maximum deceleration (where A,B are constants, v=v_0, and s=-\infty) is \frac{v_0^2}{2eB}. Use the substitution v=\frac{ds}{dt}. Homework Equations See above. The Attempt at a Solution...

Homework Statement A bullet of mass m strikes an amor plate with initial velocity v0. As the bullet burrows into the plate, its motion is impeded by a frictional force which is directly proportional to the bullet's velocity. There are no other forces acting on the bullet. -Use Newton's Second...

Homework Statement I'm only trying to answer the maximum deceleration possible question, not the rest. Homework Equations Not really sure which equations are applicable, I know the Maximum deceleration of a body in general will be a = μ*g. Although I would think that moments...

Homework Statement With how much force do I have to push a 1 kg object so that it goes 200 meters over a surface with a friction coefficient of 0.4? Homework Equations Kinematic Equations The Attempt at a Solution I listed the variables I knew off the bat mass = 1 kg distance =...

I'm making research for an article about constant acceleration / deceleration ship propulsion. Now, it's about 30 years since I was solving differential equations so there's no way I could solve, let alone devise, an appropriate differential equation. I'm not even sure an appropriate...

Hi everyone, Can anyone point me into the right direction on how to compute the deceleration parameter (##q_0##) for a radiation dominated universe? I know that q0 is given by ##q_0=-\frac{\ddot{a}(t_0)}{a(t_0) H^2 (t_0)} = - \frac{\ddot{a}(t_0) a(t_0)}{\dot{a}^2(t_0)}=\frac{\Omega_0}{2}##...

Homework Statement A building is 320 meters tall. An elevator accelerates uniformly for 30 meters, travels at a constant rate for 260 meters, then decelerates uniformly for the last 30 meters. The total time is 90 seconds. What is the velocity for the middle 260 meters? Homework...

Homework Statement A truck traveling at 40.0 m/s decelerates uniformly to 20.0 m/s over a distance of 100 m. Determine the rate of deceleration and the time required for the truck to travel the 100 m. Homework Equations Deceleration=(original velocity-final velocity)/Time The...

Homework Statement "Explain why friction is important in accelerating and decelerating a car. In your answer discuss factors affecting the magnitude of the acceleration and state the direction in which friction acts for both acceleration and deceleration. Homework Equations None, as...

Homework Statement Hi all this is just a quickie, but in one of my texts a question asks to find the maximum constant deceleration given an initial speed, time to stop and the distance it took. Now I am not sure whether to use v = u + at or s = 1/2at^2 + ut im thinking more v = u + at...

Homework Statement A man jumps from a building into a safety net located at 11m below, that acts like a rigid body when the man hits it. Find the speed. The safety net moving 1.5m meters down stops the man completely. Find the deceleration, assumed as constant.Homework Equations Vf2= Vi2+ 2ad...

Homework Statement A car traveling at 88ft/s skids 176ft after its brakes are applied. The deceleration provided by the braking system is constant. What is its value? The Attempt at a Solution $$ v_0=88 \\ v_f=0 \\ d_0=0 \\ d_f=176 $$ $$ d(t)=\int88\,dt \\ d(t)=88t+c...

Hi there, sorry for asking a question as my first post instead of contributing to the community however I have a problem which I just cannot seem to find an answer to. I am trying to model the flight of a bullet when taking into account air resistance and I am using this equation to get the...

Is there a relation between the deceleration experienced by a body in motion to the density of the medium? Stokes' law of viscosity is there for fluids. But how would one calculate the drag on a moving body in solids?

My friend and I are working on a realistic FPS sniper simulator and we wanted to be able to realistically model things like bullet drop, flight time, and impact energy. I've managed to find the drag coefficients for different rounds and I know the exit velocity, so now I want to use that to...

Yes, I'm back to this Einstein jerk, but it's in an entirely different context. Please, mentors, do not close this until my problem is resolved. Okay, when one accelerates, one feels the Einstein jerk (discussed midway through his book). When one decelerates, one feels the Einstein "jerk"...

a-c are correct but I don't know how to find part d. d)when turned off, it decelerates to a stop in 39s. What is its average angular acceleration during this time? I treated this part as part c to just find angular acceleration like normal. 371.75 rad/s / 39s=9.51 rad/s^2. should it be...

And if that is the case, why does our reference frame feel the motion, if acceleration is relative? I hope I'm explaining this the right way. I'm not saying that its being relative acceleration should shelve the notion of feeling (physical awareness of motion). But it doesn't make entire sense...

Homework Statement A certain lake is proposed as a landing area for large jet aircraft. The touchdown speed of 110 mi/hr upon contact with the water is to be reduced to 24 mi/hr in a distance of 1370 ft. If the deceleration is proportional to the square of the velocity of the aircraft...

Hi all, i think the word deceleration is used incorrectly and can cause problems for students learning physics For example, if i start from rest and run as fast as i can until i eventually more at a constant speed. Then my interperetation of this is that (i) i accelerate at some rate (ii)...

Hi all, Homework Statement The motor driving a large grindstone is switched off when a rotational speed of 360 rpm has been achieved. After 15s the speed has decreased to 210rpm. If the angular deceleration remains constant, how many additional revolutions does the stone make before coming to...

I'm just wandering. Because I have a debate with my classmate. Which one has the greater deceleration a bicycle with an acceleration of 0.5 meters per second or a car with 0.83 meters per second. I think the answer is the bicycle. :) Please give me your opinion or nearly the real answer...

Hi! This isn't exactly a homework question - I am not studying physics (though I was good at high school physics once-upon-a-time) it is just something that I am interested in and Google isn't being very cooperative. If this is in the wrong place, please let me know - I thought since it is such...

A question from my textbook states: Would the answer be -5,000 m/s^2?

Can someone please point me to a deceleration graph over the 7 minutes of terror from the 13,000 mph re-entry speed through to the parachute release and landing of the Curiosity Rover on Mars? Thanks very much. :smile: PS: Mods please feel free to move this topic to the appropriate forum...

Just throwing this out there (I'm uncertain if this has been posted before and apologise in advance if I'm just covering old topics) but I have been thinking lately about how a massive change in rotational speed caused possibly by the asteroid presumed to have wiped out the dinosaurs may help...

Homework Statement A subway train travels over a distance s in t seconds. it starts from rest and ends at rest. In the first part of its journey it moves with constant acceleration f and in the second part with constant deceleration r \, . Show that s \, = \, \frac {[\frac {fr} {f \...

Homework Statement A speed skater moving across frictionless ice at 8.7 m/s hits a 5.6 m -wide patch of rough ice. She slows steadily, then continues on at 6.0 m/s. What is her acceleration on the rough ice? Homework Equations (v1-v0)/t The Attempt at a Solution So I've...

Homework Statement An object starts at rest and accelerates at 2.5 m/s^2 for 12 seconds. It then moves at a constant velocity for 5.0 seconds and then slows down uniformly at 1.5 m/s^2 until it stops. Calculate: a) the constant velocity b) the time taken for deceleration c) the total...

Homework Statement Investigating the scene of a car accident you measure the skid marks of one of the cars to be 100.0ft long. Assuming that the maximum deceleration on dry pavement is 0.75g, what was the minimum speed of the car(in mph) when it slammed on the brakes? Homework Equations...

Hi! :) I'm confused about the direction of the friction vector when we decelerate and when we turn. I've memorized the directions (if I decelerate going east, friction is aimed west; if I am in a flat circle and going around it, friction points to the middle), but they don't exactly make sense...

Homework Statement When you slam on the brakes your car decelerates but this is not constant as it starts at a higher value and then reduces. This has something to do with the coefficient of friction between the brakes and the discs, but what is it and what are the reasons for this...

Homework Statement Using Friedmann equations find the parameter of deceleration q_0 using relative densities \Omega_M,\ \Omega_R,\ \Omega_\Lambda. Homework Equations Friedmann equations, deceleration parameter: q_0=-\frac{\ddot{a_0}a_0}{\dot{a_0}^2} The Attempt at a Solution So from...