Kinematics Definition and 1000 Threads

Homework Statement I think I made a mistake somewhere.. Homework Equations T = Jα T = F*R The Attempt at a Solution A) I started with T = Jα Since there is no slip, αm = αL Thus: Tm / Jm = TL / JL Plugging in, we find TL = Tm * JL / Jm = 2560 Now use T = F*R. Tm = Fm * Rm Plugging in...

Homework Statement Marian, who is standing on her balcony, is surprised by a pigeon and throws a flowerpot up in the air at 2.1 m/s. It takes 3.0 s for the flowerpot to smash to the ground. The flowerpot experiences acceleration due to gravity of 9.81 m/s [down]. a) How high is Marian’s...

Hello guys. i know i shouldn't be doing this, but I am asking you if you can help me with a problem for my younger sister, because my major is something else (biology, genetics) and she need this and doesn't know how to solve it.. 1. Homework Statement At an upper end of the slope inclined at...

The study of motion of objects without the reference of force and mass is called...?

Homework Statement We have that a police car is traveling at ##26.4## m/s, and that at a time, ##t=0##, a car speeds by at ##37.5## m/s. After ##1## s, the police car accelerates constantly at ##2## m/s2. We are asked to find the time, ##t##, where the police car catches the speeder. Homework...

Homework Statement Hello there physicsforums, I have a problem that I'd like feedback on as I'm not sure if I had solved it or approached it correctly. A ball that is traveling 5m/s is 30 meters above a person who is standing still. How fast must the person travel in order to catch the ball...

1. The problem statement of my lab I have this physics lab where I have to find the maximum velocity and maximum acceleration of a high school student sprinting/running using carbon tape and a spark timer. Which I already did. Now I'm having trouble developing my sources of error section. I hope...

Homework Statement "A ball is thrown vertically upward with a speed 'v' from a height 'h' metre above the ground. The time taken for the ball to hit the ground is." Homework Equations ##s = ut + \frac{1}{2}at^2## The Attempt at a Solution...

1. The problem statement, all variables and given/known G=8400N h=35m d=10m g=10m/s^2 A crane elevate a box with G=8400N at h=35. After this, the box is moved horizontal on distance 10m. No friction. Work = ? ps. Sorry for bad English. Homework Equations I think that W=W1 ( work on elevating...

Homework Statement The problem is as follows; A boy begins to walk eastward along a street infront of his house and the graph of his displacement from the house is shown in the figure. His average speed for the whole time interval is equal to...

Homework Statement [/B] A uniform cylinder with radius r is rolling down an incline without slipping as shown in diagram below. It's angular acceleration is α and acceleration of it's center of mass C is a. What will be the linear acceleration of point of contact P and another point Q on the...

Homework Statement Ok so there was a question on a physics quiz I did that I have no idea how to answer. There was a roller coaster going down a hill with an initial velocity of 1.67m/s. The hill is 60m long and had an angle of 40 degrees. There is a coefficient of friction of 0.100 with the...

Homework Statement A wheel rotates with a constant angular acceleration of π rad/s^2. During a certain time interval its angular displacement is π rad. At the end of the interval its angular velocity is 2π rad/s. What is its angular velocity at the beginning of the time interval? Homework...

Hi everyone, So far I have loved physics but I've been having trouble moving setting up the harder questions to solve for the answer. I would really appreciate the help! Thanks! :D [FONT=Palatino Linotype]A car slows down from -27.7 m/s to -10.9 m/s while undergoing a displacement of -105...

Homework Statement A motorcyclist is traveling at 15.0m/s [forward] and applies brakes. The motorcycle slows down at 5.0m/s [backward]. a) Determine the motorcycle's breaking distance [ans:23 m [forward]] Given: Vinitial: 15.0m/s [forward] a: 5.0m/s^2 [backward] Vfinal: 0 m/s [forward]...

Homework Statement "Derive the equations for position (in terms of acceleration, initial position, initial velocity, and time) and velocity (in terms of constant acceleration, a, initial velocity, v0, and time, t) from the definitions of position, velocity, and acceleration (derivative...

Homework Statement A force of friction of 3.2N acts on a 1.1Kg puck while it is sliding along a horizontal surface. If the initial velocity of the puck was 7.5 m/s, how far will the puck travel before coming to rest? Homework EquationsThe Attempt at a Solution The answer is 9.7M. Tried...

Homework Statement Horse is running in circle with constant velocity V. In the middle of circle is flashlight, lighting in all directions. Wall is set as a tangent to circle. If horse starts running from tangential point and pass 1/8 of circle, what will be speed of a shadow on the wall? Can...

Homework Statement Laura propels a stone straight up with her slingshot. The stone strikes a tree branch 4.0m above her. It strikes the branch with a velocity of 5.0m/s. How long does this take? a= -9.81 m/s2 v1 = 5.0m/s d= 4.0 m[/B] Homework Equations d=vit+1/2at2[/B] d=v1+v2/2 x t...

Homework Statement You are sliding downhill a slope of 10% (what angle is that?). Calculate how the starting velocity of 10 km/h changes within the first 120 s. After that you try to climb up an icy hill with 5% slope. Is that possible? Homework Equations Vf = Vi +At The Attempt at a Solution...

Homework Statement "a clown is shot of a cliff of height H at an angle theta and speed v. At the base of the cliff his friends are in a clown car. They start accelerating from rest one second after he is shot from the cannon. Assuming their car has constant acceleration, what is the...

Homework Statement A small spherical rock of mass collides in space with a large spherical rock of mass as indicated in the diagram. After the collision the rocks stick together to form a single spherical object. https://postimg.org/image/fltmg3bj5/ (New here so I've no clue how to upload...

Homework Statement For the mechanism shown, determine the speed and magnitude of the acceleration of collar C in terms of b, θ, θ-dot, and θ-dot-dot. Check the attached file for the diagram. We are given the length b and angle θ. Homework Equations ΣF=ma The Attempt at a Solution I...

Homework Statement [/B] I need to help solving part a) Homework Equations [/B] $$v= \frac{2\pi}{T}$$ $$(\frac{T_1}{T_2})^2 = (\frac{r_1}{r_2})^3$$ The Attempt at a Solution I'm not sure where to begin really. One approach I tried was getting T_1 in terms of v_0 and plugging it into...

Homework Statement 2 masses are connected by a spring. They are on a frictionless plane inclined relative to the horizontal by ##\alpha##. The masses are free to slide, rotate about their center of mass, and oscillate. 1. Find the Lagrangian as a sum of the Lagrangian for the COM motion and a...

Homework Statement Homework Equations $$mgh = \frac{1}{2}v^2$$ The Attempt at a Solution [/B] I'm working on a). I tried using conservation of energy to get v. $$mg(c+b) = \frac{1}{2}v^2$$ $$v = \sqrt{2g(c+b)}$$ After this I'm stuck. In order to get distance from knowing the velocity...

Homework Statement I'm trying to calculate the absolute lowest safe altitude above a planet's surface to start firing the thrusters on a simulated lander in order tot just reach vCraft = 0 at the planet's surface. The force the craft's thrusters responsible for desceleration generate is...

Homework Statement Two cars leave at the same time (one from city A and the other from city B) and drive toward each other. They first meet d=45 km far from B . Both cars reach their destination (B for the former, A for the latter) and then start driving to their initial cities.The cars have...

Homework Statement An astronaut on the moon throws a stone horizontally with a speed V0. If the acceleration due to gravity on the moon is 1⁄6 that of the Earth, by what factor will the horizontal distance traveled by the stone, d, change? Answer Options: 2 2.44 1.20 36 6Homework...

Homework Statement A uniform thin rod of Length L and mass M is pivoted at one end is held horizontally and then released from rest. Assuming the pivot to be frictionless, find a) Angular velocity of the rod when it reaches its vertical position b) The force exerted by the pivot at this time...

Homework Statement given : i need to find the trajectory formula Homework Equations i'm not sure if to use : The Attempt at a Solution [/B] I tried different options with the trigonometric identities that I have written before: thanks

Homework Statement car is braking evenly. The brakes are in locking essentially (not ABS brakes) Car is sliding under sliding friction. Car comes to a fullstop at the distance of 150m starting velocity was 100km/h (27,77m/s) calculate a) braking time b)cars deceleration c) friction coefficient...

Hello I needed to know a logical answer to the question that whether the time of flight of the objects in air increases or decreases as compared to vacuum? Why?

Homework Statement A ball is thrown horizontally wit speed 20m/s, from the top of the building which is 30m high. Find the time the ball takes to reach the ground? Homework Equations S= ut+0.5at^2 The Attempt at a Solution S=-30 u=0 A=9.8 T=? When I pluck the values I will get t^s=-30/4.9...

Homework Statement http://imgur.com/koz4PpI Homework EquationsThe Attempt at a Solution I was able to calculate the net torque on the pulley as 55.88 and the Inertia as .352. Those could be wrong, but that's as far as I could get. I really have no idea. Any kind of help/explanation would be...

I've made a drawing in order to visualize the problem better: 1. Homework Statement A car can increase its speed only at 3.00 m/s2, move at constant velocity, or decrease its speed at 7.00 m/s2. Starting at rest, the driver wishes to drive to a road sign located at x=100 m. He increases his...

Homework Statement Homework Equations N/A The Attempt at a Solution I have 2 (basic) questions about this system: 1) The question says that ωAB = ωABk, I understand that bold indicates vectors whilst the plain text indicates a magnitude so ωAB (magnitude) multiplied by k (direction vector)...

I have a question on kinematics, it is the second part of the question, there are two ways of doing the question the first way is straight forward ( one with ink writing ) but in the second method, the displacement is negative. Should it not be positive displacement? If it is negative...

[Mod Note: moved to homework forum, template missing but homework-type problem] There are two masses (m) tied at two ends of a string of length 'l'. Whole system is placed on a friction-less surface and force 'F' is applied at the centre of string in direction perpendicular to the string. Find...

Homework Statement Homework Equations Standard physics equations before forces are introduced into kinematics The Attempt at a Solution I simply looked at Chegg and could not figure out how a = 400 - kx when logic dictates that a = 400 - kx/m , since this is possibly a sum of...

Homework Statement In a playground there is a small merry-go-round of radius 1.20 m and mass 220 kg. The radius of gyration is 91.0 cm. A child of mass 44.0 kg runs at a speed of 3.00 m/s tangent to the rim of the merry-go-round when it is at rest and then jumps on. Neglect friction between the...

Homework Statement I work as a supplemental instructor for an intro physics class. As I was preparing my worksheet for this week I came across this problem. A basketball player can jump to a height of 55cm. How far above the floor can he jump in an elevator that is descending at a constant...

Homework Statement A 747 Jumbo Jet must reach a speed of 290km/h by the end of the runway to lift off. The 15L-33R runway at Toronto International Airport is 2,770 meters long. The main Toronto Island Airport runway 08-26 is 1216 meters long. Assuming the jet has a constant acceleration, for...

I have a problem where I need to figure out the initial velocity vector \vec{v_0} of a projectile, in order for it to land at the final position \vec{r_f} = x_f\hat{x} + y_f\hat{y} + z_f\hat{z}, from initial position \vec{r_0}. ___ The only knowns in the problem are \vec{r_0} and \vec{r_f}...

Homework Statement The Attempt at a Solution The above is my attempt to solve question a), is this right approach? Now all i need to do is solve for theta? Or am i completely off track? Also, i have no idea how to approach question b). some insight would be helpful... Thanks!

Homework Statement the main question asks: "If the book is initially at rest, what is its speed after it has traveled 0.400 m up the wall?" Homework Equations ∑F = m*a vf2 = vi2 + 2 * a * d , when initial velocity is 0. The Attempt at a Solution So here's my free body diagram: and out of...

Hello Forum, In kinematics, the important variables are the velocity v, the acceleration a, and the object's position x. These variables are usually presented as functions of time: x(t), v(t) and a(t). The acceleration can either be constant, or vary with time, i.e. a(t), or vary with position...

Im not sure where to find a good place to learn kinematics in one and two dimensions. Using calculus

Homework Statement A car in the northbound lane is sitting at a red light. At the moment the light turns green, the car accelerates from rest at 2m/s2. At this moment there is also a car in the southbound lane that is 200m away and traveling at a constant 25m/s. The northbound car maintains its...

Homework Statement Q; In an electron gun of television set, an electron with initial speed of 10^3m/s enters a region where it is electrically accelerated. It emerges out of this region after 1micro sec with speed of 4×10^5 m/s. (a) Find the acceleration. Homework Equations vf= vi+at The...