Kinematics Definition and 1000 Threads

you throw a ball straight up in the air with a speed of 7.25m/s. The moment the ball leaves your hand you start running away at a speed of 2.59m/s. How far are you from the ball the moment it hits the ground. So I've gotten better at these kinematics equations but this one has too many...

Homework Statement A sailboat is traveling east at 5.1m/s . A sudden gust of wind gives the boat an acceleration = (0.80 m/s2}, 40° north of east). What is the boat's direction 6s later when the gust subsides?Homework Equations Vf = V0 + atThe Attempt at a Solution To solve I simply created X...

Homework Statement A rock is tossed straight up with a velocity of When it returns, it falls into a hole deep. What is the rock's velocity as it hits the bottom of the hole? Homework Equations The Attempt at a Solution

Homework Statement 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 4.2 m/s2 for 3.2 seconds. It then continues at a constant speed for 13.2 seconds, before applying the brakes such that the...

1. Problems: A ball is launched vertically upward and returns to ground level 8 seconds later. Let upward be the positive direction. To what maximum height does the ball rise? ------------------------------------------------------------------------------------- A remote-controlled...

Homework Statement A rocket is shot straight up with an initial speed at 500 m/s. Homework Equations The equations the teacher went over beforehand were Yf = 1/2 A(T)^2 + Vi(T) + Yi Vf = A(T) + Vi The Attempt at a Solution So far I have Vf = (-9.8)(T) + 500 m/s Yf = 4.9T2 +...

Homework Statement A blue ball is thrown upward with an initial speed of 20.4 m/s, from a height of 0.5 meters above the ground. 2.5 seconds after the blue ball is thrown, a red ball is thrown down with an initial speed of 9.8 m/s from a height of 23.9 meters above the ground. The force of...

An object's motion can be described by a function that relates its position x (in meters) to time t (in seconds). Let this function be x = 6t2 + 2t + 4 What is this object's acceleration? I tried inputting 6, but it counted it wrong...

Complex physics kinematics problems help! I'm having difficulty with these physics problems. I would really appreciate it if someone could help me. Homework Statement 1) Steven throws a rock off a cliff, giving it a velocity of 8.3 m/s [down). He heard the splash when the rock hit the...

A badminton shuttle, or "birdie" is struck, giving it a horizontal velocity of 73m/s [W]. Air resistance causes a constant acceleration of 18m/s^2 [E]. Determine its velocity after 1.6s. I've used the equation V2=V1+ax x t V2= Final velocity V1=initial velocity A= Acceleration t=time...

Hello, I have problem with this example. I don't speak English very well, so please forgive me if something isn't quite enough defined - as it should be in English Physics terminology. The train moves from the station with an acceleration a. After reaching velocity v moves farther with...

Homework Statement A model rocket is launched from rest with an upward acceleration of 6.00m/s^2 and, due to a strong wind, a horizontal acceleration of 1.50m/s^2. How far is the rocket from the launch pad 6.00s later when the rocket engine runs out of fuel? Homework Equations Not sure..The...

Is it possible for velocity to be negative while the acceleration is positive? If so, then how is it possible?

A cargo plane is flying horizontally at an altitude of 10.9 km with a speed of 850 km/h when a large crate falls out of the rear loading ramp. (Ignore any effects due to air resistance.) (a) How long does it take the crate to hit the ground? (b)How far horizontally is the crate from the point...

1. While trying out for the position of pitcher on your high school baseball team, you throw a fastball at 76.4 mi/h toward home plate, which is 18.4 m away. How far does the ball drop due to effects of gravity by the time it reaches home plate? (Ignore any effects due to air resistance and...

Are ω and \dot{θ} the same in a polar kinematics? I know ω is angular speed (rad/s) and it seems to me that \dot{θ} would be the same, but in the context of rotation in polar coordinates where v = \dot{r}\widehat{r}+ r\dot{θ}\widehat{θ}, v = rω, and vθ = r\dot{θ}, that doesn't seem to be...

Homework Statement A train traveling at v0 = 22.0 m/s begins to brake by applying a velocity-dependent instantaneous acceleration a(v) = α /(v + u) m/s2, where α = – 23.0 m2/s3, v is the instantaneous velocity of the train, and u = 0.5 m/s. Determine the distance traveled by the train until it...

Homework Statement Two cars travel in the same direction along a straight highway, one at a constant speed of 55 mi/h and the other at 70.0 mi/h. How far must the faster car travel before it has a 15 minute lead on the slower car? Homework Equations average velocity=change of...

Can you answer this for me pls? I need this tomorrow and I still have so much work in hand. This questions are about Kinematics. pls help me. with solutions pls :) • The World Trade Center and the Empire State Building in the “Big Apple” have heights of 417 m and 381 m respectively. If...

Homework Statement "A particle moves in the horizontal plane that contains the perpendicular unit vectors i and j. Initially it is at the origin and has velocity 18ims^-1. After accelerating for 10 seconds its velocity is (30i + 8j)ms^-1. Assume that the acceleration of the particle is...

In an accident investigation police measured the skidmarks left my vehicle. they measure the skidmarks to be 150 m from the point where the driver applied the brakes to where the car came to rest. In their investigation the police Sumat the driver was traveling at this bead limit of 80 km/h...

Homework Statement You nose out another runner to win the 100.000 m dash. If your total time for the race was 11.800 s and you aced out the other runner by .001 s, by how many meters did you win? Homework Equations vavg=Δx/Δt v=x/t The Attempt at a Solution I have the answer already with the...

Homework Statement The driver of a truck moving at 30m/s suddenly notices a moose 70m straight ahead. If the driver's reaction time is 0.5s and the maximum deceleration is 8m/s^2, can he avoid hitting the moose without steering to one side? The Attempt at a Solution First I found out how...

Homework Statement A car moving at 60km/h meets a train of length 1km moving at 40km/h along a track parallel to the road. What distance does the car travel in passing the length of the train given that they travel a) in the same direction, or b) in opposite directions? Homework Equations...

A California Condor is approaching its nest with a large chunk of carrion in its beak. As it approaches, it makes an upward swoop, achieving a momentary upward velocity of 12.8 m/s when the carrion falls from its mouth, hitting a cliff outcropping 32.1 m below. Determine the speed of the carrion...

Homework Statement Each of the questions are either increase, decrease, equal, or undetermined. 1) You are sitting on a rotating chair, holding a 2 kg mass in each arm outstretched. When the masses are dropped, your angular momentum -------. 2) You sit in a rotating chair holding 2 kg...

I have to deal with the problem of finding an expression for the kinetic energy of a rigid body. One of its point is pivoted to a point that moves arbitrarily. So in order to find an expression for the kinetic energy I use König's theorem, but I need the velocity of the center of mass. I use...

Kinematics -- Acceleration equation confustion I have been following a derivation and can't quite wrap my head round what is happening. I don't know if the person who wrote it has made a mistake somewhere or I am making the mistake. I am informed that a = \frac{dv}{dt} Fine. Then I am told...

I feel like I'm missing a large concept of the kinematics equation. Up until today, I have only used them for HALF of a trajectory (initial velocity and final velocity of 0 at the apex). But can you use them for an ENTIRE trajectory? So say something is fired from the ground and lands on the...

I need help with this problem. Any help is greatly appreciated. Homework Statement At the instant the traffic light turns green, a car that has been waiting at an intersection starts ahead with a constant acceleration of 3.40m/s^2 . At the same instant a truck, traveling with a constant...

A car accelerates at 3 meters squared from rest for 10s. How far does it travel? a = 3 meters squared v1 = 0? v2 = ? Δd = ? Δt = 10s Why is velocity 1, 0? Why is delta t 10 seconds?

Homework Statement Initial acceleration of a particle moving in a straight line is a° and initial velocity is zero. The acceleration reduces continuously to half in every t° seconds. What will be the terminal velocity(v)?Homework Equations \intadt=\intdvThe Attempt at a Solution...

Homework Statement A body standing on a bridge throws a stone vertically upwards with a velocity of 20 m/s. it strikes the water below after 3 seconds, the height of the bridge over the water level in the river is : a. 45 m b. 10 m c. 5 m d. 15 m Homework Equations vf^2= 2aS +...

The percentage errors in the measurement of mass and speed are 2 % and 3% respectively.how much wil be the maximum error in the estimate of kinetic energy obtained by measuring mass and speed? its ans is 8 % .. according to this equation K = mv^2/ 2 , so dK / K = dm/m + 2dv / v ( d means...

Homework Statement Tarzan (63.0 kg) is trying to save Jane (50.0 kg) from the fast approaching crocodile (who is in the crocodile pit). Tarzan starts from rest at point A and swings off the edge of a cliff 30.0 m above the ground, while hanging on to a vine of a very large tree. At point B...

Homework Statement There are three particles along the x-axis ordered from back to front, A, C, B. A travels at 4/5c and B travels at 3/5c, the speed of particle C is unknown. What must the speed of particle C be such that A and B will arrive at C at the same time? And, at what speed will both...

Physics Kinematics Question! :) (Check my work?) Homework Statement A ball is thrown vertically up from a window that is 3.6 meters above the ground. The ball's initial velocity is 2.8 m/s up. What is the ball's velocity when it hits the ground? How long after the first ball should a second...

Homework Statement The velocity of particle is 0 at t=0. Then , (a) The acceleration at t=0 must be zero. (b) The acceleration at t=0 may be zero. (c) If the acceleration is 0 from t=0 to t=10 s , the speed is also zero in this interval. (d) If the speed is 0 from t=0 to t=10 s...

1-D Kinematics Problem/Free Fall. "A helicopter carrying Dr. Evil..." NOTE: I'm new here and I wanted to make sure I am not breaking the rules: I show most of my work step by step for this problem since there are so many things going on in it. My question is whether or not my though process is...

A runner hopes to complete the 10,000m run in less than 30.0 minutes. After exactly 27.0 minutes, there are still 1100m to go. The runner must then accelerate at 0.20m/s^2 for how many seconds in order to achieve the desired time. I have calculated the runner moving at 5.5m/s^2 for the...

why does this kinematics problem seem impossible.HELP! Homework Statement If the man's mass is 70 kg, if L is 0.4 m h is 0.6 m, what is the downwards force (assumed constant) exerted by his feet during the phase A to B? State any physical law or principle you use in obtaining your answer...

Hi there, Sorry for so many questions, but I feel frankly stupid for getting these wrong, and yet I have no clue why they're so off. Any ideas of why the answers are what they are? Thanks so much. 15. A truck starts from rest and accelerates at 1.5 m/s2for 20 s. It then travels at constant...

Homework Statement At a carnival, you can try to ring a bell by striking a target with a 9.00 kg hammer. In response, a 0.400 kg metal piece is sent upward toward the bell, which is 5.00 m above. Suppose that 25.0% of the hammer's kinetic energy is used to do the work of sending the metal...

Homework Statement An extreme skier, starting from rest, coasts down a mountain that makes an angle of 25.0° with the horizontal. The coefficient of kinetic friction between her skis/snow is 0.200. She coasts for a distance of 10.4 m before coming to the edge of a cliff. Without slowing down...

Does anyone know of any worked out examples for the calculation of the width of a 1->3 decay process, where ALL THREE masses are included? I can find a LOT of examples where they let the masses go to zero, (like leptonic/semi leptonic decays, decays to pions, etc). This makes the integrals...

Homework Statement An airplane flies at an air speed of 300 miles per hour, in the direction toward southwest. There is a head wind of 75 mi/hr in the direction toward due east. (A) Determine the ground speed. (B) Determine the direction of motion of the plane, expressed as an angle...

Homework Statement Two points P and Q have position vectors in a reference frame that are given by rOP = 50ti and rOQ = 40i - 20tj meters. Find the minimum distance between P and Q and the time at which this occurs. Homework Equations The Attempt at a Solution I suppose I take the...

A ball is thrown downwards from a top of a 20m building with an initial velocity of 15m/s. What equation could be used to model its height? My answer: h (t) = -4.9t2-15t+20

Homework Statement Block A weighs 75lbf and the coefficients of static and kinematic friction between A and the plane are both 0.50. Determine the acceleration of A under the action of the 25 lbf force when the velocity at A is (a) 8fps up the plane, (b) 15 fps down the plane. (c) Zero...

Homework Statement I am unable to solve part b and please help me check whether is there anything wrong with my graph..:redface:The Attempt at a Solution Segment A Vi=0 V=3 S=60 a=9.81 v=vi+at 3=0+9.8(t) t=0.305s Segment B Vi=3 V=0 a=-2 v=vi+at 0=3-2t t=1 t=1+0.305=wrong answer :cry: