Kinematics Definition and 1000 Threads

  1. Gbox

    Finding the diferencial function of a moving particle

    Homework Statement A particle is moving in a liquid ##a=-kv## when ##k## is a constant, if a constant force is being apply on the particle ##a=-kv+\frac{F}{m}##. 1. for the formula that's include the force, find the diferencial function where ##v## will appear in it explicitly, ad its...
  2. trinkleb

    Rotational Kinematics - angle between force and velocity

    Here is the problem I am working on. I have found answers for all of them except part (f), which is the one I need help with. I will report the answers I have so far: A classic 1957 Chevrolet Corvette of mass 1240 kg starts from rest and speeds up with a constant tangential acceleration of 2.00...
  3. S

    How Long Did It Take for the First Revolution of a Computer Disk Drive?

    Homework Statement A computer disk drive is turned on starting from rest and has constant angular acceleration. If it took 0.680s for the drive to make its second complete revolution, how long did it take to make the first complete revolution? (t=?) Homework Equations Θ=(ct^2)/2 (i think) The...
  4. C

    How Does the Jacobian Process Work in Kinematics?

    Hey guys, Im studying for an exam and don't fully understand the jacobian process. Speciffically how you can differential the middle colum with respect to theta_3. Please view attached. So from step 1 to 2. Thanks.
  5. vetgirl1990

    Meaning of y-int. on graph of acceleration vs. hanging mass

    Homework Statement In an experiment, I measured the effect of mass on the acceleration of a cart, rolling down a leveled air track. I then graphed acceleration vs. mass (m'), where: m' = m / (M+m); M = mass of the cart, m = hanging mass, which was increased with subsequent trials. Homework...
  6. vetgirl1990

    Finding launch angle from vertical and horizontal distance

    Homework Statement The mountain rescue officers trigger the avalanche by firing a gun at a distant mountain slope. The muzzle velcoity of the gun is 225m/s. The horizontal and vertical distance from the gun to the slope is x=1,072m and y=538m respectively. Find the lowest angle between the...
  7. M

    I'm curious what anyone gets for part d

    Homework Statement After a wild ride on a windsurfer, you head to a lifeguard tower to fly a kite. You stand on the tower, which is 3 meters above the ground and release your kite. You let out 10 meters of string and the kite begins moving according to the following equation: y(t) = (0.9...
  8. K

    Determining velocity for a pulley/rope system

    The Question: Using a simply pulley/rope system, a crewman on an Arctic expedition is trying to lower a 5.65-kg crate to the bottom of a steep ravine of height 23.9 meters. The 60.9-kg crewman is walking along holding the rope, being careful to lower the crate at a constant speed of 1.50 m/s...
  9. M

    Understanding distances, derivatives, and integrals help?

    Homework Statement Two railroad tracks intersect at right angles at station O. At 10AM the train A, moving west with constant speed of 50 km/h, leaves the station O. One hour later train B, moving south with the constant speed of 60 km/h, passes through the station O. Find minimum distance...
  10. tk24700

    1 dimensional kinematics with car and motorcycle

    Homework Statement Two friends agree to test their physics background in 1D motion. Steve, is a distance d ahead of Jack. Jack is driving at a constant, know velocity v0 when they start their experiment. At this moment, Steve accelerates from rest with his motorcycle in such a way that they...
  11. snowsnowrain

    Who Threw the Ball First in This Physics Puzzle?

    Homework Statement A child stands on a balcony directly above a friend 5.00 m below. Each throws a ball toward the other with the same initial speed of 10.0 m/s. If each catches a ball at the same instant, which child threw a ball first? How much later was the second ball thrown? Homework...
  12. W

    A problem on two dimensional kinematics

    Homework Statement A block is given initial velocity of 5m/s up a frictionless 20 degrees incline. How far up the incline does the block slide before coming to rest? The answer is 3.73m. I set the coordinates to be perpendicular to the plane instead of parallel to the incline. I calculated...
  13. I

    What Angle Below the Horizontal Does a Hockey Puck Hit the Ground?

    Homework Statement A hockey puck slides off the edge of a table with an initial velocity of 20 m/s. The height of the table above the ground is 2 m. At what angle below the horizontal does the puck hit the ground? Homework Equations d=Vi(t)+(1/2)at^2 a^2+b^2=c^2 The Attempt at a Solution...
  14. B

    Linear kinematics problem with limited variables.

    A rock is dropped from a cliff of height h. At the same time a rock is thrown straight up from the bottom with an initial velocity. Assuming they meet, at what time will they meet. V1 = 0 A = -9.82 Thats all you have across both rocks... is this even possible. You probably have to do some...
  15. toboldlygo

    "A woman throws a ball at a vertical wall...." Proj. Motion

    So, I've already answered parts (b) and (c), but I'm struggling with (d). Thanks in advance for any help! 1. Homework Statement "A woman throws a ball at a vertical wall d = 6.0 m away. The ball is h = 3 m above ground when it leaves the woman's hand with an initial velocity of 16 m/s at 45°...
  16. C

    Straight Line Kinematics Problem

    Homework Statement [/B] A baseball pitcher throws a ball at a speed of 47m/s. When the catcher receives the ball, he pulls his hand back through a distance of 0.035m in the process of making the catch. What was the acceleration of the ball as it was being caught, assuming the acceleration was...
  17. toboldlygo

    Instantaneous Velocity from Strobe Diagram

    Hi guys! My first post here. I've been frequenting Physics Forums and have found a wealth of information, and I'm hoping I can get some specific help about this concept. Thanks! Homework Statement "Cart A and B move along a horizontal track. The top-view strobe diagram below shows the...
  18. Dhyan Patel

    Grade 12 Kinematics Vector Problem....

    Homework Statement An airplane travels at 885 km/h [W35S]. Wind blows against the plane with a velocity of 150 km/h [E55N]. What's the displacement with direction? Homework Equations v=v1^2+v2^2sqrtThe Attempt at a Solution
  19. M

    How Long Does It Take a Ball to Hit the Ground If Thrown Downward?

    Homework Statement A ball is thrown down with an initial velocity of 2.0 m/s from a height of 1.75 m, determine how long until it hits the ground. initial velocity = 2 m/s distance = 1.75 m acceleration = 9.8 m/s2 time = ? Homework Equations d=vit+1/2a(t)2 The Attempt at a Solution 1.75=2t +...
  20. K

    Half atwood machine with accelerating pulley

    Homework Statement [/B] Consider a half-atwood machine on a cart as below, with mass m_2 attached to M via a frictionless track that keeps it pinned to M but allows it to move vertically. All surfaces (except between the wheels/ground) are frictionless, and the pulley and rope are massless. If...
  21. P

    Inverse Kinematics: Understanding the Math Behind Building Virtual Arms and Legs

    Hey guys, So, I'm new here. And I'm of 13 years of age. I am a programmer in a platform called "ROBLOX". I wanted to create my own Animator within that platform, using Inverse Kinematics. However, searching through the web, everything is just so complicated to me. I don't seem to understand the...
  22. romiomustdie

    How Do You Derive the Distance Traveled by a Projectile in a Viscous Liquid?

    i have found out the second answer of the PHYSICS problem but unable to solve the first part.i tried all possible ways.:-( ---------------------------------------------- a test projectile is fired horizontally into a viscous liquid with a velocity Vo . The retarding force is proportional to the...
  23. M

    Equations of Kinematics in 2-D/Projectile Motion

    Homework Statement A tennis ball is struck such that it leaves the racket horizontally with a speed of 28.0 m/s. The ball hits the court at a horizontal distance of 19.6 m from the racket. What is the height of the tennis ball when it leaves the racket? Homework Equations v = vo + at x =...
  24. M

    Two rocks launched up/collison (Kinematics)

    Homework Statement This is a quiz question that was given in my AP physics C class. "A rock is launched upward with a speed V0. With what velocity must a second rock be launched from the same initial position at time T later so that it hits the first rock when it has a velocity of -V0/2."...
  25. MMVS

    Kinematics question about a runner

    Homework Statement A sprinter can accelerate with constant acceleration for 3.00 s before reaching top speed. He can run the 100-meter dash in 10 s. What is his speed as he crosses the finish line? Homework Equations The Attempt at a Solution So I broken up the question into two parts, one...
  26. TheNeezoMan

    If there is no acceleration, does that mean no force?

    So last year, I was told by a friend that no Acceleration means no Force, Mathematically, this makes sense (500 Kg * 0 m/s^2 = 0 N), but intuitively, I can't wrap my head around it. Maybe this is because of language and the way we use the word force in normal conversation, but in physics it is...
  27. S

    What Is the Change in Velocity and Acceleration of a Rebounding Ball?

    Homework Statement A ball moving westward at 36 m/s hits a wall and rebounds at 27 m/s, eastward. (a) What is the change Δv in the vector velocity? (This is effectively the velocity of the rebounding ball relative to an image of it passing through the wall unaffected. It’s not the same as the...
  28. S

    How Far Will the Cart Travel at Increased Speeds?

    Homework Statement A cart is initially moving at 0.5 m/s along a track. The cart comes to rest after traveling 1 m. The experiment is repeated on the same track, but now the cart is initially moving at 1 m/s. How far does the cart travel before coming to rest.[/B]Homework Equations W=ΔKE[/B]...
  29. MARK 42

    Kinematics -- Projectile motion problem

    One bullet was fired from Gun A and Gun B each at varying time interval. Both the guns are 10 meters above the ground. Calculate: a) Which gun was fired first. b) Displacement and time at which the two bullets will collide.
  30. C

    How do I solve these problems (kinematics)

    Homework Statement She drives for 40.0 min at 80.0 km/h, 10.0 min at 75.0 km/h, and 30.0 min at 45.0 km/h Determine the average speed for the trip The attempt at a solution I got 66.25khm by ((4*80)+(75)+(3*45))/8 which looks like its in the ballpark range but when I enter the answer for my...
  31. I

    Kinematics problem: x(t) --> v(t) --> a(t)

    1. Problem statement: an object moves along the x-axis so it's position at any given moment is x(t) = −t3(to the third power) + 6t − 12 m. a. what is it's velocity at any given moment b. what is it's acceleration c. at what moment does the object stopsHomework Equations s=vt+1/2at2 The Attempt...
  32. D

    How high and how fast will a 25 kg rocket fly without air resistance?

    Homework Statement A 25 kg Rocket generates 400 N of thrust. It is designed to burn its fuel for 40 seconds. If launched vertically what will its final vertical velocity be when the fuel runs out? How high can it fly? How long until it reaches the ground? Neglect mass of fuel, and air...
  33. Anama Skout

    Is Special Relativity Correct for Observer A?

    So let's say you're sitting on the ground (observer A) and there's a car or something that moves at .99c (observer B). (Of course, this is all hypothetical) Now, my interpretation goes that when A is seeing B, the information he gets is distorted, namely due to time dilation, length contraction...
  34. Yohanesnuwara

    #1 An Advanced but Simple Motion-in-1D Problem (1)

    I get these physics problems from Engineering Physics Course at my recent university, Bandung Institute of Technology, Indonesia. The questions are really simple but needs an advance and deep analysis to answer them. The system of answering the science problems here in my university is quite...
  35. Anama Skout

    A juggler throws a bowling pin straight up in the air....

    Homework Statement A juggler throws a bowling pin straight up in the air. After the pin leaves his hand and while it is in the air, which statement is true? (a) The velocity of the pin is always in the same direction as its acceleration. (b) The velocity of the pin is never in the same...
  36. D

    How Do You Solve a Kinematics Tennis Ball Problem Using d-v-a-t Formulas?

    Homework Statement ) You are given the task of shooting a tennis ball from ground level through 2 hoops. The two hoops’ centers and the launch site are located in the same vertical plane, and the hoops are oriented perpendicular to the ball’s proposed trajectory and also in a vertical...
  37. Anama Skout

    My possible misunderstanding on a freely falling object

    Consider the famous kinematics equations $$x_f=x_i+v_i\cdot t+\frac12at^2$$ My question is: does this equation work for every point A & B along the parabola formed when dropping an object?
  38. R

    Kinematics in one direction - relative velocity word problem

    Homework Statement Danielle bikes at a steady rate of 4.0 m/s south along the bank of a river. Summer is rowing her kayak heading south down the river; she can row at a constant rate of 2.0 m/s in still water. There is a 5.0 meter wide bridge that spans the river and the bike trail. a) If it...
  39. J

    Kinematics car acceleration question

    Homework Statement For part c ii) of this question, the new distance is now 1/4 of the previous distance as both acceleration are the same. But why are both the acceleration the same? Homework Equations v^2= u^2 +2as The Attempt at a Solution I know that the method is by using the above...
  40. Jabran Shakil

    Kinematics 1-D Problem. Stuck on specific parts.

    Two cars start from rest at a red stop light. When the light turns green, both cars accelerate forward. The blue car accelerates uniformly at a rate of 3.1 m/s2 for 3.7 seconds. It then continues at a constant speed for 12.5 seconds, before applying the brakes such that the car’s speed decreases...
  41. S

    How Far Does a Ball Travel After Rolling Off an Incline?

    Homework Statement A 30 degree inline sits on a 1.1 meter high table. A ball rolls of the incline with a velocity of 2m/s. How far does the ball travel acoss the room before reaching the floor?Homework Equations deltax= vot + 1/2at^2[/B] The Attempt at a Solution...
  42. R

    Equations of Kinematics, including gravity

    Homework Statement A hot-air balloon is rising upward with a constant speed of 2.20 m/s. When the balloon is 3.30 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground? Homework EquationsThe...
  43. N

    Solving a Kinematics Problem: Throwing a Ball to Clear a Peaked Roof

    Homework Statement A peaked roof is symmetrical and subtends a right angle, as shown. Standing at a height of distance h below the peak, with what initial speed must a ball be thrown so that it just clears the peak and hits the other side of the roof at the same height? Diagram...
  44. A

    I solved few questions on kinematics -- Is my working correct?

    So the first question is: A student standing on the platform of a railway station notices the first two carriages of an arriving train pass her in 2.0 s and the next two in 2.4 s. The train is decelerating uniformly. Each carriage is 20 m long. When the train stops, the student is opposite the...
  45. Adoniram

    Two Potentially Easy Kinematics Problems (sliding/rotation)

    Question 1: 1. Homework Statement A bug of mass m crawls radially outwards with a constant speed v’ on a disc that rotates with a constant angular velocity ω about a vertical axis. The speed v’ is relative to the center of the disc. Assume a coefficient of static friction μ, find out where on...
  46. Priyadarshini

    A Ball Is Thrown Vertically Upwards, Find The Ratio of PE to KE

    Homework Statement A ball of mass 65 g is thrown vertically upwards from ground level with a speed of 16 m s–1. Air resistance is negligible. The ball takes time t to reach maximum height. For time t 2 after the ball has been thrown, calculate the ratio of the potential energy of ball to the...
  47. Titan97

    Constraint Equations Homework: v0, v1, v2

    Homework Statement Block C is moving with a velocity v0 and block A and B are moving with velocities v1 and v2 with respect to block C. Find the relation between v0, v1 and v2 Homework Equations none The Attempt at a Solution Since the string is in-extensible, its velocity at both ends...
  48. Remixex

    Who Wins the Drag Race Based on Constant Acceleration?

    Homework Statement I stumbled upon a problem and i can't establish the ODE to solve it, from there on i believe i can solve the ODEs if they have regular analytical solving methods (translated from Spanish, will sound a bit weird) Car race, 2 pilots (a and b) participate in a drag race. They...
  49. H

    How Does Projectile Velocity Change Before and After Maximum Height?

    Homework Statement The magnitude of the velocity of a projectile when it is at its maximum height above ground level is 14 m/s. (a) What is the magnitude of the velocity of the projectile 1.2 s before it achieves its maximum height? (b) What is the magnitude of the velocity of the projectile...
  50. H

    Another Kinematics Problem (I have solution)

    Homework Statement A parachutist bails out and freely falls 59 m. Then the parachute opens, and thereafter she decelerates at 2.7 m/s2. She reaches the ground with a speed of 3.1 m/s. (a) How long is the parachutist in the air? (b) At what height does the fall begin? Homework Equations...
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