Kinematics Definition and 1000 Threads

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...

Homework Statement A ball starts from rest and rolls down a hill with uniform acceleration, traveling 150 m during the second 5.0 s of its motion. How far did it roll during the first 5.0 s of motion? Vi= 0 at time t=5s -> d= 150 m Homework Equations d=vf+vi/2 * t The Attempt at a...

Homework Statement In Example 2.6, we considered a simple model for a rocket launched from the surface of the Earth. A better expression for a rocket's position measured from the center of the Earth is given by Y(t)=(RE3/2+3(√g/2)REt)2/3 where RE is the radius of the Earth (6.38 ✕ 106 m) and g...

I'm an avid bike rider and a first year physics student. A couple days ago a friend of mine told me about how his friend was going downhill on her bike, used her front brake, and went over. I would like to determine what the minimum speed for a given slope angle is for the biker to do a full...

Homework Statement While standing at the edge of the roof of a building, you throw a stone upward with an initial speed of 6.91 m/s. The stone subsequently falls to the ground, which is 16.5 m below the point where the stone leaves your hand. At what speed does the stone impact the ground? How...

So this question has two parts. The first I got without any trouble: "Two objects move with initial velocity of -8.00 m/s, final velocity of 16.0 m/s, and constant accelerations. (a) The first object has displacement 20.0 m. Find its acceleration." I used The formula Vf2=Vi2+2aΔx and got an...

Homework Statement Ball A is projected vertically upwards at a velocity of 15 m/s from the ground. Ignore the effects of air resistance. One second after Ball A is projected, a second ball B, is thrown vertically downwards at a velocity of 9 m/s from a balcony 30m above the ground. Calculate...

Homework Statement A skier leaves the ramp of a ski jump with V=10.0 m/s at 15° above the horizontal. Slope of mountain below ramp is 50°. Assuming air resistance is negligible, find distance from end of ramp at which skier lands. Homework Equations 1. sf = si + vist + ½ast2 2. tanΘ =...

Homework Statement I have chosen my axis as you can see on the picture. To the left, it is the positive 'r'-axis, up is the positive 'y'-axis. I have to calculate the angular speed. My solution is correct, but I'm getting into trouble at the end. I have to take the roots of the last equation to...

Homework Statement A rock is thrown straight upward from the edge of a 30m cliff, rising 10m, then falling all the way down the base of the cliff.Homework EquationsThe Attempt at a Solution Well, because the rock was thrown 10m up, and then it came all the way down, I added those quantities...

Homework Statement When accelerating upward off a trampoline, how would you depict this on an acceleration-time graph? I know kinematics is the study of motion without a strict regard to the forces that are capable of changing motion, but according to Newton's 2nd law, an object accelerates in...

Homework Statement The human organism can handle acceleration that is 4 times bigger than gravitational acceleration. What is the smallest radius of curvature that can handle pilot of an airplane that files with constant speed of 1000 km/h? Homework Equations This task seems easy but I don't...

Homework Statement A 250 kg box slides down the ramp and then across a level floor. The coefficient of kinetic friction along the floor is 0.20. A person see the box moving at 1.0 m/s(left) and pushes on it with a horizontal force of 140 N (right). How far does the box travel before coming to...

Homework Statement Eliminate t from the equation (x-xi)=vi(t)+1/2(a)t^2 using the kinematic equation v=vi+at to get v^2=vi^2+2a(x-xi) The Attempt at a Solution I wind up with (x-xi)=vi(v-vi/a) + 1/2(v^2-vi^2/a). If the first term on the right side didn't exist, I could see what the solution...

Homework Statement I am stuck with this task please help me. 1. A body is moving with constant deceleration while passing through path that contains two same parts and each one of them is 10m. The first part of the path, body passes for t1= 1s and the second part passes for t2=2.2s. Determine...

Homework Statement Concept Simulation 2.3 provides some background for this problem. A ball is thrown vertically upward, which is the positive direction. A little later it returns to its point of release. The ball is in the air for a total time of 8.21 s. What is its initial velocity? Neglect...

A ball is rolling over a soccer field with constant velocity Vb > 0 at an angle of 45° to the goal line. It starts at the corner of the field (distance d from the middle of the goal line) at the time t0 = 0. At the same time a player starts heading towards the goal on a path perpendicular to the...

Homework Statement A train that runs 140 km / h requires about 700m to stop. Calculate the average acceleration of the train while braking.Homework Equations v: x/t[/B]The Attempt at a Solution v= x/t so t= x/v= 700m/ (38.89m/s)=18 s Now to find acceleration a= v/t a= 38,89m/s / 18s =2,160...

Homework Statement A sled starts from rest and slides down an inclined plane with constant acceleration. In three seconds, it has traveled 9m. How long does it take to reach a velocity of 24m / s? Homework Equations d = vi * t + ½ * a * t^2, vi = 0[/B] vf = vi + a * t, vi = 0 The Attempt...