Kinematics Definition and 1000 Threads

Homework Statement This isn't so much of a problem as a general question. I am trying to find the starting velocity of a spinning ball going upwards (in air, close to Earth's surface, only force acting on it is the gravitational force) until its linear velocity reaches zero. I found the initial...

Homework Statement You're at a mission control for a rocket launch, deiciding whether to let the launch proceed. A band of clouds 5.3km thick extends upwards from 1.9km altitude. The rocket will accelerate at 4.6ms^-2 and it isn't allowed to be out of sight for more than 30s. Should the...

Homework Statement A balloon is rising at 10m/s when its passenger throws a ball straight up at 12m/s relative to the balloon . How much later does the passenger catches the ball? Homework Equations The Attempt at a Solution vf^2 - vi^2 = 2g(yf-yi) Ball: 0ms^-1 - (22ms^-1)^2 =...

Homework Statement Two divers jumped from a 3m platform. One jumps upward at 1.8ms^-1 and the second steps off the platform as the first passes it on the way down. a) What are their speeds as they hit the water? b) Which hits the water first and by how much? Homework Equations...

Homework Statement You're atop a building of height, h, and a friend is poised to drop a ball from a window at h/2. Find an expression for the speed at which you should simultaneously throw a ball downward, so the two hit the ground at the same time. Homework Equations None The Attempt at a...

Homework Statement A falling object travels one-fourth of its distance during the last second of its fall. From what height was it dropped? Homework Equations none The Attempt at a Solution yf - yi = vit + 0.5gt^2 0.25x = 0 + 0.5(-9.8ms^-2)(1)^2 x = 19.6m

Homework Statement You're speeding at 85km/h when you notice that you're only 10m behind the car in front of you which is moving at the legal speed limit of 60km/h. You slam on your brakes and your car negatively accelerates at 4.2m/s/s. Assuming the other car continues at constant speed, will...

Good afternoon! I've been mulling over this question for a bit and I can't seem to understand what it is asking. This is a question for an introductory calculus-based physics university course. 1. The Problem: A uniform disk, such as a record turntable, turns 8.0 rev/s around a frictionless...

After 35mins of runnin, at the 9km point in a 10km race, you find yourself 100m behind the leader and moving at the same speed. What should your acceleration be if you're to catch up by the finish line? Assume that the leader maintains constant speed.

Homework Statement A puck moving at 32m/s slams into a wall of snow 34cm thick. it emerges moving at 18m/s. Assuming constant acceleration, find a) time taken for puck to spend in the snow (ans:0.014s got it) b)the thickness of a snow wall that would stop the puck entirely Homework...

Hi, I'm an undergraduate commencing my first year in Astrophysics and Mathematics. It's the summer break as of now and I'm doing some self-study on the relevant topics when school commences. Homework Statement On packed snow, computerized antilock brakes can reduce a car's stopping...

Homework Statement A stack of two blocks sits on a frictionless surface; however, between the two blocks is a kinetic coefficient of friction μk. External force F is applied to the top block. During the time the force is applied, the top block is displaced by x1, and the bottom block is...

Homework Statement A phonograph turntable with an initial angular velocity of 78 rpm continues turning for 40 rotations after being switched off. What is the angular deceleration of the turntable? Assume constant angular deceleration. Homework Equations \alpha=(\omega-\omega0)/t...

Homework Statement A mass slides down a segment of a circle starting from rest at A. It has a radius of R. Find the speed of the mass at the bottom ignoring friction. Also, find the time for the ice cube to go from A to B. As far as solving for the time I am told not to calculate the...

I am not sure where else to post this. Hopefully this is not in the wrong place. I am student teaching in a physics classroom this week. I will be teaching about scalars vs. vectors, calculating average velocity, and calculating acceleration. As I plan my lessons, I've realized they are...

Homework Statement A turntable is a uniform disc of mass m and radius R. The turntable is initially spinning clockwise when looked down on from above at a constant frequency f_0. The motor is turned off at t=0 and the turntable slows to a stop in time t with constant angular deceleration...

Grade 11 Physics Final Project. Help! (Kinematics) first of all, I am new to the forum. and i was wondering if i should post this on homework forum or general physics. then i decided to post it here. so i have been working on a final project for my grade 11 physics. the teacher wants us...

Homework Statement A motorcyclist accelerates rapidly so the bike entirely rests on the back wheel, while the midpoint of the back wheel O' accelerates with constant acceleration a_o' horizontally. The entire bike rotatoes with angular velocity \frac{d}{dt} \theta and angular acceleration...

Homework Statement [/B] Hey guys, so here is my question: A huntsman fires a gun pointing at a monkey hanging on the branch of a tree. The huntsman and the base of the tree are on a flat horizontal. At the moment the huntsman fires the gun, the monkey will release it's grip on the branch of...

Homework Statement Two cars start from rest and travel in opposite directions. Car A travels at 6m/s^2 to a maximum of 30m/s. Car B travels 5m/s^2 to maximum of 35m/s. 200m between them. When will they meet? Homework Equations d=vt d=vit + 1/2 at2 The Attempt at a Solution at 6...

Homework Statement Consider a system of two masses joined by a massless string with the string passing over a massless frictionless pulley with a radius of 5.0 cm. The mass of the left is 9.00 kg and the mass on the right is 1.60 kg. Find the angular acceleration of the pulley when the...

Homework Statement I am stumped on a problem (number 13 page 49) from the Serway/Vuille/Faughn text College Physics 8th Ed. The problem is A person takes a trip driving with a constant speed of 88.5 km/h, except for a 22 min rest stop. If the person's average speed is 77.8 km/h, how...

Homework Statement You're driving down the highway late one night at 18m/s when a deer steps onto the road 41m in front of you. Your reaction time before stepping on the brakes is 0.5s and the maximum deceleration of your car is 12 m/s/s Homework Equations 1) How much distance is...

Question: "A man steps from the top of a tall building. He falls freely from rest to the ground, a distance of h. He falls a distance of h/4 in the last 0.800 s of his fall. Neglecting air resistance, calculate the height h of the building. I've attempted the solution in a number of different...

Homework Statement A cat spots a flowerpot that sails first up and then down past an open window. The pot is in view for a total of .50s and the top-to-bottom height of the window is 2.00m. How high above the window does the flower pot go? I was trying to help one of my friends with...

Homework Statement A proton (charge +1e and mass 1.67e-27kg) and an alpha particle (charge +2e and mass 6.64e-27kg) are placed 3 fm (1 fm=10e-15m) apart. a)what is the force on each particle B)what is the potential energy of the system? c)what is the acceleration of each particle at the...

Homework Statement A rocket is launched straight up with constant acceleration. Four seconds after liftoff, a bolt falls off the rocket. The bolt hits the ground 8 seconds later. Three seconds after the bolt falls off, the rocket's engines fail. How high does the rocket go before it begins...

1. Problem The kicker stands 50 m from the goalpost that is 3 m high. She kicks with an initial velocity of 24.5 m/s. She just makes the goal height-wise, but did the ball travel far enough? She kicked at an angle of 35.28 degrees. 2. Homework Equations S = (1/2)at^2 + V0t + S0 S =V0xt...

Homework Statement A weather rocket is launched straight upwards. The motor provides a constant acceleration for 18s, then the motor stops. The rocket altitude after 26s after launch is 5800m. What was the rocket's acceleration during the first 18 seconds? Homework Equations [ tex ]x =...

Homework Statement You're driving down the highway late one night at 18m/s when a deer steps onto the road 45m in front of you. Your reaction time before stepping on the brakes is 0.50s and the maximum deceleration of your car is 12m/s^2. a)How much distance is between you and the deer when...

On a test today I came across a rather ridiculous question, in which I chose the incorrect answer. The problem is, based on my understanding of kinematics I am unsure as to why I got it wrong.1. The question stated: Miley Cyrus (not kidding) suddenly falls out of a tree at the exact time that a...

a boat takes 3.1 hours to travel 15 km down a river, then takes 5.1 hours to travel the same distance upstream. how fast is the river traveling. I found the boat is traveling at 4.84km/hr down the stream and 2.94 km/hr up it. not sure where to go next. Any help would be appreciated.

Here is the question: I have posted a link there to this topic so the OP can see my work.

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)...

Homework Statement Car A is located 43km away, 17 degrees north of west. Car B is 34km away, 38 degrees east of north. The person in car A checks the position of car B by using a GPS. What does it give for car B's a) distance from car 1 b) direction, measured due east? Homework Equations...

Homework Statement a baseball player hits a home run that just clears a fence that is 19.0 meters high.The fence is located 128 meters from the home player(where the ball is hit). The ball was hit at an angle of 37.0 degrees above the horizontal from a height of 0.900 meters above the ground...

Homework Statement A rifle is aimed horizontally at a target 50m away. The bullet hits the target 2.5cm below the aim point. A) Find the bullets flight time. B)Find the bullets initial velocity upon leaving the barrel. Homework Equations Projectile kinematic equations/ The Attempt at a...

Homework Statement Sam is running at 3.8 m/s and is 75m behind John who is running at a constant velocity of 4.2m/s. If Sam accelerates at 0.15m/s^2, how long will it take him to catch John? Homework Equations d = (vf+vi/2)t vf = vi + at d = vit + 1/2at^2 vf^2 = vi^2 + 2ad d = vft -...

Homework Statement A student riding a bicycle begins to go downhill and accelerates at a rate of 1.8m/s2. If the acceleration lasts for 2.4s, and the final speed of the bicycle is 10.2m/s, at what speed was he initially travelling? a = 1.8 t = 2.4 vf = 10.2 vi = ? Homework Equations...

I don't know what to do for these three questions and they're due on Wednesday Homework Statement a. A sprinter can accelerate with constant acceleration for 2.28s before reaching top speed. He can run 148.0m in 16.6s. What is his speed as he crosses the finish line? b. A car...

I'm using a Quantum Physics student textbook for physics at school. My class started with Kinematics and I want to know what pages I should read to better understand the topic.

Homework Statement A man decided to run a marathon. (a) What was his average speed, in m/s, for the first 5K? (b) At 5K, was he speeding up or slowing down? Explain. Homework Equations a) change in distance/time b) acceleration = change in velocity/ change in timeThe Attempt at a Solution...

Homework Statement A pole-vaulter leaves the ground with an upward speed of 9.5 m/s. (a) How fast is she going when she is 2.0 m above the launch point? (b) How long is required to reach this height? (c) Why are there two answers to (b)? The Attempt at a Solution Question A and...

Homework Statement You throw a snowball with an initial speed of 15.0 m/s. Your enemy's head is located 20m away, approximately horizontally. At what angle should you throw the snowball (ignore air resistance)? Homework Equations vf=vi+at d=vit+(1/2)at^2 The Attempt at a Solution

Im sorry I just realized this is in the wrong subforum... Homework Statement Hello Everyone! I am new here and am having trouble with this webassign question. I was able to work out the answer to the first two but the last two are giving me trouble. I am not sure if this is right subforum to...

Hello everyone, I've run across an interesting Newtonian physics problem that I'd like some input on. The problem begins with a rotating object. Let's assume it is a slender rod rotating about one end with a given mass (m), length (L) and rotational speed (ω). This results in the rod having...

Homework Statement A cross country team race is about to begin and team Beta decides to use their one-dimensional kinematics knowledge that they learned from their first year physics course. Each team consists of two people and one horse. The clock is started when the team crosses the...

Homework Statement I know pictures aren't the best, but here it is. Homework Equations The Attempt at a Solution This is my work for this problem. Disregard the drawing as it isn't right. I'm not sure if I'm misinterpreting the horizontal range part or what. I feel pretty...

Kinematics question -- Rocket launch Homework Statement A rocket starts from rest and moves upward from the surface of the earth. For the first 10s of its motion, the vertical acceleration of the rocket is given by ay=(2.70m/s3)t, where the +y-direction is upward. A.What is the height of the...

kinematics question -- An automobile accelerating and braking Homework Statement According to recent test data, an automobile travels 0.250 mi in 19.9 s, starting from rest. The same car, when braking from 60.0 mi/h on dry pavement, stops in 146 ft. Assume constant acceleration in each part...