Kinematics Definition and 1000 Threads

  1. W

    MHB Kinematics + Trigonometry Application (Physics 12u)

    Show that the maximum range of a projectile launched with Vi from Yi=0 is 45 degrees. (HINT: sin20 = 2sinθcosθ)
  2. T

    Basic Kinematics - shouldn't there be a constant?

    Homework Statement Homework Equations a=dv/dt, v=dx/dt, x=integ(vdt) The Attempt at a Solution We were given the above problem and solution. Everything seems very straightforward. My question is this: should the function for acceleration also include a constant, e.g. [/B] ? None of the...
  3. Z

    Kinematics in Cylindrical Coordinates

    Homework Statement A small bead of mass m slides on a frictionless cylinder of radius R which lies with its cylindrical axis horizontal. At t = 0 , when the bead is at (R,0), vz = 0 and the bead has an initial angular momentum Lo < mR sqrt(Rg) about the axis of the cylinder where g is the...
  4. C

    Hard Kinematics problem: Ball thrown into the air

    Homework Statement A person throws a ball up from a height of 1.5 meters, 3.23 seconds later, the ball hits the ground next to you. Find the maximum height the ball reaches. Homework Equations V=V(initial)+at The Attempt at a Solution This problem almost seems impossible without knowing what...
  5. M

    Struggling with Biomechanics? Get Expert Help Here!

    Hello! I am a third year kinesiology student who is struggling with her biomechanics assignment. Mind you, I haven’t studied physics or trigonometry in four years since i left high school so I really need some help.
  6. jybe

    Calculating Safe Distance for Warning: Flower Pot Falling from 21.6m Height

    Homework Statement A flower pot is knocked off a window ledge from a height d = 21.6 m above the sidewalk as shown in the figure below. It falls toward an unsuspecting man of height h = 1.71 m who is standing below. Assume the man below requires 0.300 s to respond to a warning. How close to...
  7. L

    Calculate velocity of stopping car

    Homework Statement A car moving at 20m/s starts decelerating, travels distance d, and stops. Find the car’s velocity at distance d/2. Homework EquationsThe Attempt at a Solution my brain is fried. I feel like I’m missing something obvious but I just don’t get it.
  8. opus

    1-D Kinematics: Trains and a bird

    Homework Statement Two trains, each having a speed of 30km/h, are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 60 km apart and heads directly for the other train. On reaching the other train, the bird flies directly...
  9. S

    Friction and kinematics problem

    Homework Statement What minimum time is required to move a weight of mass 50 kg over a distance of 10 meters along a horizontal floor if the rope used to pull it breaks when the tension exceeds 20kgf, while a force of 10kgf is sufficient to start the weight moving or move it uniformly...
  10. J

    Conservation of Momentum (Explosion Kinematics)

    Homework Statement [/B] A 3200 kg space vehicle (including a launchable lifeboat) is traveling with a velocity of 300 m/s in a straight trajectory [East]. The lifeboat (200 kg) is fired at a speed of 1000 m/s [N of original trajectory]. a) After firing it is found that the horizontal...
  11. R

    Find the initial velocity of a water rocket (mass changes)

    Homework Statement Find the initial velocity of the boost phase (when water is coming out). Here is everything I know - Mass of rocket with no water is 0.13kg, mass of rocket with water is 1.1kg. The total length of the rocket is 0.48m. The time to the maximum point is 3.46 seconds, and total...
  12. TachyonLord

    Find the average force at distance x

    Homework Statement A “superball” of mass m bounces back and forth with speed v between two parallel walls, as shown. The walls are initially separated by distance l. Gravity is neglected and the collisions are perfectly elastic. If one surface is slowly moved toward the other with speed V...
  13. Tyrannosaurus_

    Intro kinematics problem - is this ok?

    Homework Statement On a North-South highway, a Car drives 80 km/h [N]. A SUV, that is north of the Car, is moving 70 km/h [South]. The car is to the south of the SUV. The two are separated by 20 km. Where are the two cars when they pass each other. Homework Equations Both are in uniform...
  14. PhysicsKT

    Really interesting and tough kinematics problem

    Homework Statement Three ants A, B and C are crawling on a large horizontal tabletop always occupying vertices of an equilateral triangle, size of which may vary with time. If at an instant, speeds of A and B are vA and vB, prove that vC>= vA+vB. Homework Equations Well, that's what I don't...
  15. J

    Minimum deceleration to prevent a collision

    Homework Statement At a given time ##t=0##, a car 1 moving with constant velocity ##v_{1}## breaks with constant deceleration ##d##. Another car 2 at a distance ##L## behind car 1 and traveling with constant acceleration ##a_{2}## and velocity ##v_{2}## at ##t=0## brakes immediately as soon as...
  16. Fabrizio Vassallo

    Meaning of a phrase in a kinematics problem

    1. Problem statement: "An object is thrown horizontally with an initial speed of 10 m/s. How far will it drop in 4 seconds?" Homework Equations Δx = v0x.t Δy = v0y.t + 1/2(-g)t2 The Attempt at a Solution [/B] When I first read it, I thought that 'how far' means Δx, since when someone says...
  17. J

    Optimizing Periodic Motion in an Elliptical Orbit

    Homework Statement A particle moves periodically around an ellipse of equation ##\frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1##. You can assume ##a>b##. The ##x## and ##y## components of the particle's velocity can never exceed ##v## at any point. What is the minimum possible period of the...
  18. J

    Maximum and minimum speeds in a moving cube

    Homework Statement A rigid cube in the figure moves in space. At a certain time ##t## its front face ##ABCD## is vertical and the velocity of vertex ##A## is vertical down ##v## while the velocity of its vertex ##D## makes an angle with the vertical and has magnitude ##v_{2}## while lying on...
  19. J

    Acceleration of a particle on a parabola

    Homework Statement A particle moves along a parabola on the x-y plane with equation ##y^{2}=2px## with constant speed ##1000m/s##.What is the magnitude of its acceleration? Homework Equations Parametric equations ##\vec{r}=(b^{2}t^{2}/(2p),bt)##. The Attempt at a Solution...
  20. W

    MHB Kinematics Application Question - Physics 11u

    In a 100 meter race, Maggie and Judy cross the finish line in a dead heat, both taking 10.2 seconds. Accelerating uniformly Maggie took 2.00 seconds and Judy 3.00 seconds to attain maximum speed, which they maintained for the rest of the race. a)What was the acceleration of each sprinter...
  21. J

    How Late Did the Man Arrive to Catch the Train?

    Homework Statement A man arrives ##T## seconds late to a train station. He watches the last three cars of the train pass by. The next-to-the-next-to-last car takes time ##t## to pass by the passenger, the next-to-last car takes time ##t'## to pass by and the last car takes time ##t''## to...
  22. C

    What is the net acceleration of the coin on a rotating disk?

    Homework Statement A disk is initially at rest. A penny is placed on it at a distance of 1.4 m from the rotation axis. At time t=0s, the disk begins to rotate with a constant angular acceleration of 1.9 rad/s^2 around a fixed, vertical axis through it's center and perpendicular to it's plane...
  23. L

    I get two different answers when solving a kinematics problem

    1. A car accelerates for 200 meters and has an initial velocity of 2.0 m/s and a final velocity of 6 m/s. What is the acceleration of the car if this change in velocity takes 12 seconds?Homework Equations a=Δv/Δt Δx=Vi*t+.5at2[/B]The Attempt at a Solution When I solve this using the first...
  24. E

    Kinematics: find the particle's position as a function of time

    Homework Statement There is a particle that moves in 1-dimension. mass is m, force on the object is given as a function of position(x), Fx= -mω2x.(ω is constant) when t=0 particle has x0>0, and velocity is zero. find the particle's position as a function of time. Homework Equations There is a...
  25. AntSC

    Modifying Newton's Kinematic Equations for High Altitude

    I recently watched a video on youtube where a guy fires a 50 cal. rifle straight up into the air and measures the time of flight at about 100s. It got me thinking about what altitude the round reached. So I used the kinematics equations and obtained a value of 12.25km. Amazing, but I wondered...
  26. solarmidnightrose

    B Understanding Kinematics in Calculus for High School Students

    hi, I'm a high-school student that is just beginning to learn calculus. in calculus we are learning how to apply integration and diffrentiaiton methods regarding kinematics. there is this certain phrase i do not really understand in our textbook: e.g."in the second second" how am i meant to...
  27. devilish_wit

    I have a hard time with kinematics involving inclined planes

    Homework Statement Two blocks of mass m1 = 3.00 kg and m2 = 6.00 kg are connected by a massless string that passes over a frictionless pulley (see the figure below). The inclines are frictionless. Image - https://www.webassign.net/serpse9/5-p-049.gif The inclined plane is shaped like a...
  28. V

    Complex Kinematics and Dynamics

    Homework Statement Two pucks (5 kg each) made of Teflon are on a long table, also made of Teflon. Puck A is sitting at rest on the left end of the table. Puck B is 15 m away at the right hand end of the table, and is travelling toward Puck A with an initial speed of 0.5 m/s. A person on the...
  29. V

    Complex Kinematics and Dynamics

    Homework Statement Two pucks (5 kg each) made of Teflon are on a long table, also made of Teflon. Puck A is sitting at rest on the left end of the table. Puck B is 15 m away at the right hand end of the table, and is travelling toward Puck A with an initial speed of 0.5 m/s. A person on the...
  30. L

    Was the Driver Speeding Before the Crash?

    Homework Statement "Based on the following data, determine if the driver who crashed was driving over the speed limit" The relevant data given is: -A 2002 Volvo t-bones a truck in an alley with a speed limit of 20km/h -An eyewitness heard tires screech, then a loud bang, and also said the...
  31. M

    How do we find the uncertainty of v in the kinematics eqn?

    Homework Statement Given the kinematics equation v2 = u2 + 2as, find the uncertainty Δv. Given: Values of a, s, u, and their associated uncertainties. Homework Equations v2 = u2 + 2as The Attempt at a Solution I'm aware of the rules for uncertainty propagation, but what do I do in this case...
  32. alexi_b

    Finding when acceleration is zero

    Homework Statement A block of mass 2.42kg is accelerated across a rough surface by a rope passing over a pulley, as shown in the figure below. The tension in the rope is 13.9N, and the pulley is 12.3cm above the top of the block. The coefficient of kinetic friction is 0.395. A: 2.28 m/s^2...
  33. alexi_b

    How far apart are the astronaut and satellite after 8.67 minutes?

    Homework Statement A 63.8kg spacewalking astronaut pushes off a 678.0kg satellite, exerting a 156.0N force for the 0.870s it takes him to straighten his arms. How far apart are the astronaut and the satellite after 8.67min? Homework EquationsThe Attempt at a Solution I tried just finding the...
  34. P

    How do you find the acceleration needed to clear a jump?

    Homework Statement Homework Equations The Attempt at a Solution I used Pythagorean theorem to find the length of the ramp (25^2+18^2 = √949) and found the angle of elevation using tangent (Tanθ=18/25) but then got stuck on what formula to use.
  35. K

    Kinematics within a simulation

    Homework Statement I'm simulating a warehouse (in Unity) where forklifts and other vehicles transport stuff from point A to point B. The routes are modeled as a graph with vertices and edges. Every transport is saved as a task in a backend system with the relevant data such as starting time...
  36. S

    What is the total torque of that system?

    Homework Statement A load was put on the right side of a seesaw 0.6 meter from its center as shown, on the other side a force of 49N is applied perpendicular to the seesaw surface 1 meter from its center, the setup is tuned to an angle of 30 from the horizontal axis as shown. On the right...
  37. Z

    Kinematics Problem: Train braking and blocking an intersection

    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...
  38. Abhimessi10

    Charge entering into the field between capacitor plates

    Homework Statement A negative charge of mass m enters into the field between two deflecting parallel plates with length 'l' separated by distance 'd' with a velocity 'v'.Assuming electric field to be uniform,find the maximum charge so that it will not hit a plate Homework Equations Kinematic...
  39. J

    How Do You Calculate the Meeting Point of Two Stones Thrown from a Cliff?

    Homework Statement Two stones are thrown simultaneously, one straight upward from the base of a cliff and the other straight downward from the top of the cliff. The height of the cliff is 6.00m. The stones are thrown with the same speed of 9.0m/s. Find the location (above the base of the cliff)...
  40. L

    Kinematics: find maximum height

    Homework Statement A rocket takes off from the launch pad and moves directly upward with an acceleration of 29.4 m/s2. It runs out of fuel after 4s and continues to coast upward, reaching a maximum height before falling back down to Earth. a) Find the rocket's maximum height. b) What is the...
  41. gibberingmouther

    Understanding the 1-D Kinematics Equations

    So, the equations I'm talking about are the "big 4" listed here: https://www.physicsclassroom.com/class/1DKin/Lesson-6/Kinematic-Equations I understand how to derive all these using calculus or algebra and graphs. That's not my problem. I can apply them pretty well to problems I need to...
  42. M

    Kinematics: baseball toss with an angle provided

    Homework Statement An outfielder throws a baseball to his catcher in an attempt to throw out a runner at home plate. The ball bounces once before reaching the catcher. Assume the angle at which the bounced ball leaves the ground is the same as the angle at which the outfielder threw it as shown...
  43. DracoMalfoy

    Projectile Motion Kinematics: A catapult launches a rock....

    Homework Statement A catapult launches a rock with an initial velocity of 50m/s at 35 degrees above the horizontal. The rock must clear 3.5m at 10m away in order to make it over a castle wall to get to the enemy. Do the knights succeed? By how much do they clear the wall or miss clearing the...
  44. DracoMalfoy

    Kinematics: Ball thrown off of a building

    Homework Statement A ball is thrown off of a building in the +x direction at 10m/s. If the ball takes 2s to land, how tall is the building? Homework Equations Vf=Vi(a)(t) Δd=Vi(t)+1/2(a)(t) Vf^2=Vi^2+2(a)(Δd) Δd=1/2(Vf-Vi)(t) The Attempt at a Solution Vf: 0m/s Vi: 10m/s a: -9.8m/s^2 t: 2s...
  45. DracoMalfoy

    Projectile Motion Kinematics: Finding maximum height

    Homework Statement A ball is kicked with an initial speed of 20m/s at an angle of 50° above the horizontal. What maximum height does the ball reach? Homework Equations Vfx=VicosΘ Δx=VicosΘt Vfy=(VisinΘ)+ay⋅t (Vfy)^2=(VisinΘ)^2+2ay⋅Δy Δy=1/2(Vfy+(VisinΘ))⋅t The Attempt at a Solution I...
  46. DracoMalfoy

    Kinematics: Motion in One Direction: Car Chase

    Homework Statement A car traveling at a constant speed of 24.0m/s passes a trooper hidden behind a billboard. One second after the speeding car passes the billboard, the trooper sets off in a chase with a constant acceleration of 3.0m/s^2. A) How long does it take the trooper to overtake the...
  47. baldbrain

    'They' haven't considered centripetal acceleration

    Homework Statement A train is moving counter-clockwise with a constant speed of 10 m/s in a circle of radius ##\frac {16} π## m. The plane of the circle lies in the x-y plane. At time t = 0, the train is at P, when a stone is thrown from it with a speed of 10 m/s relative to the train towards...
  48. DracoMalfoy

    Kinematics: Two engines, One Rocket, and Displacement.

    Homework Statement A Rocket with an engine that causes a net acceleration of 4m/s^2 launches with an initial velocity of 20m/s. The engine fuel lasts for 0.8s. A secondary engine then fires causing a net acceleration of 2m/s^2 for 0.6s How far off the ground is the rocket when the secondary...
  49. DracoMalfoy

    Trouble with another Kinematics question

    Homework Statement A person riding a bike travels at an average velocity of 3m/s for 30min. The person then takes a water break for 15 min. The person finally travels a distance of 450m at an average velocity of 1.5m/s. What is the persons average velocity? 2. Homework Equations [/B] Average...
  50. john-b

    Inconsistency in a Velocity-Time Graph

    Homework Statement We're supposed to convert a position-time graph to a velocity-time graph to an acceleration time graph. These are the values for the position-time graph: Homework Equations m = y2-y1/x2-x1 The Attempt at a Solution I found the slopes for each time which were 5, 8.5, 17...
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