Kinematics problem Definition and 279 Threads

Alice, Bob and Daniel are standing on the edge of a canyon which is 100m deep and 20m wide. On the opposite side of the canyon there is a 10m high cave, 15m below the top of the cliff. They each throw a rock horizontally with the following initial speed to see who can get it into the cave...

Two rugby players are running towards each other. They are 37m apart. If one is accelerating from rest at 0.5m/s^2, and the other was already moving at 3.1 m/s and maintains his speed, How long before they hit each other? (if someone can guide me step-by-step that'd be great) (sorry...

consider a river flowing with a speed u along positive X axis . a man starts swimming from a point on the bank of the river ( which is considered to be as origin ) . l is the width of the river and the velocity of man is always directed towards the point (0,l) . find the equation of the path...

i need to make a model for predicting the time taken for a ball to roll a certain distance up a ramp, i can't work out how to get time in terms of initial velocity, acceleration (const.) and displacement. how do i make t the subject in s = ut + 1/2 at^2 or ios there another equation i...

Can someone tell me if I'm right? 0.98 seems a bit high for the coefficient of friction? A 25kg sled is pulled at a steady 1.3 m/s by a rope inclined 40 degrees above horizontal. If the pulling force is 26.7 N, what is the coefficient of friction between the sled runners and the snow? m...

hi please can sum one help me, a stone is dropped from he top of a cliiff at rest another stone it thrown downwards from the same point at 11ms-1. The two stones land at the same time, what is the height of the cliff,:frown: how do u work this out i have no idea,:cry: thankyou in...

Hello, thanks for reading =) Let's just jump into it... At the instant the light turns green, a car accelerates from rest at a rate of 1.8m/s^2. A truck gets to the intersection by the time the light changes [and therefore doesn't have to stop]. The truck is traveling at a constant velocity...

So the problem is this: A rocket is launched straight up with a constant acceleration. Four seconds after liftoff a bolt falls off the rocket and hits the ground 6 seconds later. What was the rockets acceleration? Well the initial velocity of the rocket is 0m/s and the velocity of the...

Hello, I've been working on the following problem for quite some time, with no success: A commuter train travels between two downtown stations. Because the stations are only 1.15 km apart, the train never reaches its maximum possible cruising speed. The engineer minimizes the time t between...

A motorist is traveling at 10 meters a second when he sees a deer in the road 50m ahead. If the maximum negative acceleration of his vehicle is -7 meters per second per second, then what is the maximum reaction time delta t of the motorist that will allow him to avoid hitting the deer? I am...

A rifle is aimed horizontally at the centre of a large target 200m away. The initial speed of the bullet is 500 m/s. (a) Where does the bullet strike the target? (b) To hit the centre of the target, the barrel must be at an angle above the line of sight. Find the angle of elevation of the...

Hi, i have some questions for the following problems. A car accelerate at -1.9 m/s2. Traveling at a constant velocity of 32 m/s, this car comes up behind a car traveling at a constant velocity of11 m/s. a) How close to the slower car can the driver of the faster car come before applying...

Hi, I attempted this problem, but I do not see how it makes sense. Could somebody give me an idea of how to solve this problem? Thanks! While traveling along at 24.3 m/s, a 13.7 kg car runs out of gas 16 km from a service station. Neglecting friction, if the station is on a level 14.8 m above...

rotational kinematics problem I am stuck on please help! my problem says this: -a pendulum consisting of a string of length L attached to a bob of mass m swings in a vertical plane. When the string is at an angle Theta to the vertical, A) what ist he tangential component of acceleration of...

hi guyes, I was wondering if someone could help me with a problem I had on a quiz. The question he's been puzzeling me for some time now. A ball is thrown upward in an open roof elevator traveling at 10m/s(elevator speed). The balls speed is 20m/s. How much time does it take for the ball to...

Hello everyone, this problem may seem simple to all of you, but I seem to be having a mental block. My physics prof assigned some review last class and I seem to be stuck on this problem. Here goes: When a high speed train traveling at 161km/h rounds a bend, the engineer see that there is a...

In diving to a depth of 635 m, an elephant seal also moves 590 m due east of his starting point. What is the magnitude of the seal's displacement? Would I just take the 590m and subtract if from 635m to get the answer? Is the answer 45m?

Problem: The acceleration of a particle is given by Ax(t) = -2.00m/s^2 + (3.00m/s^2)t. A) Find the initial velocity such that the particle will have the same x-coordinate at t= 4.00s as it had at t= 0. B) What will the velocity be at t= 4.00s? Work so far: Integrated to get these: Vx(t)...

Encountered the following question. For (a), I repetitively found the answer 12 for magnitude of displacement and 131° for the direction; after being told i was incorrect...i need help: :confused: Path A is 8.0 km long heading 60.0° north of east. Path B is 6.0 km long in a direction due...

A man who can row 4 miles per hour in still water finds that he can row upstream in 7 and 1/2 hours a distance which requires 2 and 1/2 hours to row downstream. Find the rate of the current. When I saw the problem at once I had dozens of ideas to solve it but all of them failed. Can you...

I am [make that: WAS] having difficulties solving Problem 87 from Chapter 2 of Physics for Scientists and Engineers by Paul A. Tipler, 4th edition. The statement of the problem is as follows: Ball A is dropped from the top of a building at the same instant that ball B is thrown vertically...

I am having difficulties solving the first part of Problem 83 from Chapter 2 of Physics for Scientists and Engineers by Paul A. Tipler, 4th edition. The statement of the problem is as follows: A passenger train is traveling at 29 m/s when the engineer sees a freight train 360 m ahead...

A rifle is aimed horizontally at the center of a large target 200 m away. The initial speed of the bullet is 500 m/s. Where does the bullet strike the target? To hit the center of the target, the barrel must be at an angle above the line of sight. Find the angle of elecation of the barrel. So...

A ball is throw horizontally from the top of a building 35 m high. The ball strikes the ground at a point 80 m from the base of the building. Find the ball's initial velocity. What I have done so far is to find the time it takes for the ball to reach the ground, using the x=V0t + 1/2 at^2...

A hunter aims directly at a target (on the same level) 120 m away. (a) If the bullet leaves the gun at a speed of 300 m/s, by how much will it miss the target? (b) At what angle should the gun be aimed so the target will be hit? Im havin a little trouble here. I think you are supposed to...

I found this problem in the text "Elementary Physics Classical and Modern" by Weidner and Sells. Two automobiles are both moving at 90 km/h in the same direction, one directly behind the other. The driver of the lead car suddenly applies his brakes, decelerating at 7.5 m/s^2. The other...

A wheel has eight spokes and a radius of 38.0 cm. It is mounted on a fixed axle and is spinning at 2.80 rev/s. You want to shoot a 27.0 cm long arrow through the wheel, parallel to this axle, without hitting any of the spokes. Assume that the arrow and the spokes are very thin and evenly spaced...

Please help me...I've been struggling for a long time over this following problem... Some cockroaches can run as fast as 1.5 m/s. Suppose that two cockroaches are separated by a distance of 60 cm and that they begin to run toward each other at the same moment. Both insects have constant...

Here's a problem that I just can't seem to get. I just need to get started out. A placekicker is about to kick a field goal. The ball is 26.9 m from the goalpost. The ball is kicked w/ a initial velocity of 19.8 m/s at an angle theta above the ground. Between what two angles, theta1 &...