Initial velocity Definition and 451 Threads

Homework Statement I am very lost and would love help. Given in the description is;"A golf ball leaves a golf club at an angel 30 degrees above the horizontal and lands on the green 150 meters away initial position." With this information i am supposed to find the balls initial velocity, how...

Homework Statement A rock is thrown horizontally from a tower point A, and hits the ground 3.5 s later at point B. A line from A to B makes an angle of 50 degrees with the horizontal. Compute the magnitude of a initial velocity u of the rock. The Attempt at a Solution I started looking at the...

Homework Statement A fireworks rocket is launched vertically upward, and explodes into two equal-mass pieces at the top of its trajectory. The pieces hit the ground at t1 and t2 seconds after the explosion. What is the rocket’s launch speed? Assume no air resistance. Homework Equations v1 =...

Homework Statement A stone is dropped from the top of a tall building. It accelerates at a rate of 9.81m/s^2. How long will the stone take to pass a window that is 2.0m high, if the top of the window is 20.0m below the point from which the stone was dropped? I've already solved the initial...

Homework Statement A ball is thrown upwards. Its velocity at 3/5 its max height is 16.0m/s What is its initial velocity? What is its max height? Homework Equations vf^2 = vi^2 -2g(yf-yi) define up as positive The Attempt at a Solution I ran through numerous attempts on paper but can't...

NOTE: The subject should say Inelastic Collision 1. Homework Statement A 980kg sports car collides into the rear end of a 2300kg SUV stopped at a red light. The bumpers lock, the breaks are locked, and the two cards skid forward 2.6m before stopping. The police officer, estimating the...

Homework Statement A footballer kicks the rock off the cliff, with a horizontal velocity. The cliff's height is 40.0m. The rock falls in a lake. The footballer hears the "splash" 3.00s later. Sound travels through air with a velocity of 343 m/s. What is the rock's initial velocity? a = -g =...

It is my understanding that to calculate the change of kinetic energy of an object that speeds up from vi to vf you use this formula: Change of kinetic energy = 1/2 * m * (vf2 - vi2) When the initial velocity is 0 m/s I have no problems, but let's say an object that weighs 2 kg speeds up from...

Homework Statement If you know the acceleration of a car and its initial velocity, you can predict which of the following? A. The direction of the car's initial velocity B. The magnitude of the car's final velocity C. The displacement of the car D. All of the above Homework Equations I said...

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 A helicopter is flying in a straight line over a level field at a constant speed of 6.8 m/s and at a constant altitude of 9.4 m. A package is ejected horizontally from the helicopter with an initial velocity of 12.0 m/s relative to the helicopter, and in a direction opposite...

Homework Statement Kit the cat is going to jump through a hoop. He begins on a wicker cabinet at a height of 1.745 m above the floor and jumps through the center of a vertical hoop, reaching a peak height 3.115 m above the floor. With what initial velocity did Kit leave the cabinet if the...

Hi I'm trying to solve a problem but I'm a bit confused about this part: Suppose you are walking at a speed of 2 m/s when you drop the ball that you were holding in your hands. Is the initial velocity 0 m/s? In the textbook it says that initial velocity for dropped objects is 0 m/s but that...

Homework Statement Disk P (inertia 0.41 kg ) moves at an unknown velocity across a low-friction horizontal surface and collides with disk Q (inertia 0.75 kg ), which is initially at rest. After the collision, the two (now slightly dented) disks move apart without spinning. Velocity information...

Homework Statement A bobsled glides down a hill with an acceleration of -4.5 m/s If it stops after 5 s, what was its initial velocity? 2. Homework Equations i know vf(final)= v + at The Attempt at a Solution i multiplied -4.5m/s by 5s and i got the correct answer the only problem is the...

Homework Statement A 1350kg car traveling at 72km/h collides with a slow-moving car of mass 1650kg, also initially traveling south. After the collision, the velocity of the 2 cars together is 24km/h. Determine the initial velocity at which the second car was travelling. Given: m1=1350kg. vi1 =...

Homework Statement A 1000kg car is moving at 25ms when a net force of 200N acts to slow the car. This force acts while the car moves through a distance of 300m. Find the new speed. Homework Equations Kinetic Energy equation v2=u2+2as The Attempt at a Solution Attempted the use of Kinetic...

Warren falls over his tackle box and lands in a canoe 0.95 m below the side of the dock. Warren's mass is 70 kg and the canoe has a mass of 72 kg. Warren and the canoe move 1.73 m away from the dock in 1.005 seconds. relating equations are Vi = Vf - at v = d/t A = change in velocity/time...

Homework Statement how to know that the nozzle increases the velocity of water by 6 times? it's not given ... and no data for initial velocty given Homework EquationsThe Attempt at a Solution

Homework Statement What initial velocity has to have a ball at the height h=1m in order to sink in the water to depth of s=4m? How long is the motion of a ball through water? A ball is made of material that has density \rho=770 kg/m^3. Surface tension and friction are negligible. Homework...

***Sorry I meant to say finding time when you have initial velocity and position*** 1. Homework Statement A test rocket is launched by accelerating it along a 200.0-m incline at 1.36 m/s2 starting from rest at point A (the figure (Figure 1) .) The incline rises at 35.0 ∘ above the horizontal...

Homework Statement A football started on the ground 64 yards from the base of the goal post and barely clears the 10 ft high bar. The initial trajectory of the football was 43 deg above the horizontal. What was its initial speed? Homework EquationsThe Attempt at a Solution (vf)^2 = (vi)^2 +...

This question is on space and projectiles. It is about comet 67P/ Churyumov-Gerasimenko and the Rosetta/ Philae lander. Question: 67P has a gravitational field strength of 5.2x10^5 N/Kg. After Philae bounced it took 1 hour 50 minutes to reland. Calculate the initial velocity of Philae. Does this...

Homework Statement A German U2 rocket from WW2 had a range of 300km, reaching a maximum height of 100km. Determine the rocket's maximum intial velocity. X component variables: di=0, df=300, a=0, time=9, vi=? Y component variables: a=-9.8, vf=0, vi=?, di=0, df=100, displacement=100, Note: For...

Homework Statement Homework Equations I know that this could be solved through kinematics. The Attempt at a Solution I thought that I could use the range equation to solve for Vo, but since there is an initial height, I don't think that could work. I thought that maybe I could use the...

Homework Statement A referee throws a ball in a basketball game. When the ball was in his hand the heigh was 1,6 meters above the ground. The ball is caught 0.8 seconds later by a jumping player. The ball is 2.7 meters above the ground and on the way down. what was the initial velocity when the...

Homework Statement We need to fin the initial velocity of a water fountain. The data I have collected is: Height (bottom to apex)= 0.042 m Distance (from spout to end on the stream)= 0.112 m Time (it takes to travel)= .25 seconds Angle the water shoots from= 50 degrees Here is more if it...

Homework Statement Frog jumps in air to 1m height. Neglecting air resistance find initial speed the instant it leaves the ground. a= -9.8m/s^2 d= 1m vi=? Homework Equations d=1/2(vf+vi)t d=1/2at^2 + vi(t) + di The Attempt at a Solution I figured that since acceleration is 9.8m/s, I could just...

Homework Statement A hole is punched in a full milk carton, 10cm below the top. What's the initial velocity of outflow? Homework Equations P2 = P1 + ρgh Conservation of energy of fluids: P2 + 1/2ρv22 + ρgy2 = P1 + 1/2ρv12 + ρgy1 The Attempt at a Solution Set the top of the carton as P1, and...

Homework Statement So there are two planets A and B whose centres are 6r apart. A and B has the same mass M and radius R. What is the minimum velocity(from the surface of B) of the rocket required to launch it from B so that it reaches A ? Homework Equations F=GmM/R^2 The Attempt at a...

Homework Statement A 1500-kg sedan goes through a wide intersection traveling from north to south when it is hit by a 2200-kg SUV traveling from east to west. The two cars become embellished due to the impact and slide as one thereafter. On-the-scene measurements show that the coefficient of...

Hi! I just started studying physics in German, and I am stuck about basic formulas partially because of the language. 1. Homework Statement A ball is launched from the ground at a speed |vb0| = 90m/s with an angle of β = 50° to the horizontal axis x. At a distance of d = 60m is placed a...

I've put the problem statement below and worked it out. I typically don't post questions like this as they're a lot to go through, but I am wondering if I have worked the problem correctly as my book does not have the solution and I feel like I am not understand the material correctly. 1...

Homework Statement I need to find two ways to calculate initial velocities (2 versions) of an object just clearing over a 9.99 m wall. Homework Equations kinematics equations The Attempt at a Solution Way 1 I was trying is to say dx = 40m , dy = 10m, ay= -9.81m/s^2. The thing is, I can't...

Homework Statement What is the initial velocity of the ball just as it enters the screen? The Job Using your understanding of projectile motion along with some background research on video analysis, devise a way to find the initial velocity of the tennis ball in the video just as it enters...

So if you have an object in a hot air balloon that it traveling upwards at constant velocity, and this object falls out of the hot air balloon, is its initial velocity 0 or is it the same as that of the balloon? Thanks in advance!

I've been trying to come up with the answer but it hasn't gotten me anywhere. I know that I need to find the angle to get the velocity. Q: A rock is projected from the edge of a 30.48 m tall building at some unknown angle above the horizontal. 5 seconds after, the rock strikes the ground at a...

Homework Statement A flat roof has a height of 65m above the ground. A tennis ball rolls off the edge of the roof and hits the ground at a point 418m horizontally from the edge of the roof. A.) How much time is the ball in the air? B.) What is the magnitude of the initial velocity?[/B]2. The...

Homework Statement At which minimum velocity should you throw the ball horizontally if you are standing on a hemispherical rock of radius R so that it at no point touches the rock and lands at the minimum distance from the rock horizontally. Find the expression that solves for initial velocity...

Homework Statement A plane with an initial velocity of (225m/s ŷ + 325m/s Ẑ) intercepts a 20kg piece of luggage with initial velocity of (-75m/s ŷ - 15m/s Ẑ). After, plane is moving at speed 400 m/s. What is the mass of the plane? Homework Equations momentum y: Mplane(225m/s) + 20kg(-75 m/s) =...

Homework Statement Hello, usually when solving basic velocity problems, if the object starts from rest, then its initial velocity would be 0. But why is it that, if a cat were to leap from rest, its initial velocity wouldn't be 0, but something else? My friend told me about muscle...

Hi! I'm working on a problem for class and am having trouble figuring out how to calculate the initial velocity, which I need in order to calculate acceleration and from there the value of an unknown force. I thought I was on the right track, but my professor reminded me that I need to use the...

Homework Statement A locust jumps at an angle of 43.8 degrees and lands 1.0 m from where it jumped. If it jumps with the same initial speed at an angle of 62.4 degrees, how far would it jump then? X-component knowns: Initial velocity = v(cos(43.8)) displacement = 1m angle = 43.8 degrees...

Homework Statement In a classroom demonstration, a glider moves along an inclined track with constant acceleration. It is projected from the low end of the track with an initial velocity. After 8.2 s have elapsed, it is 103.3 cm from the low end and is moving along the track at a velocity of...

An object fired at an angle of 30° above the horizontal takes 2.5 s to travel the last 12 m of its vertical distance and the last 10 m of its horizontal distance. With what speed was the object launched? (Note: This problem does not stipulate that the initial and final elevation of the object...

Homework Statement A football is kicked at an angle of 60 degrees to the horizontal and travels a distance "R" before hitting the ground A.) find the initial speed of the football Homework EquationsThe Attempt at a Solution : [/B] I would presume I would need to find initial velocity of X...

Question: A car of mass 1500kg collides head-on with a truck of mass 9000kg. After the collision, the wreckage is at rest. The speed of the car just before the collision was 30m/s. What was the speed of the truck just before the collision? Relevant Equation(s): m1v1+m2v2 = m1v1'+m2v2' (?) My...

Hi! First post on this forum, though not the first time visiting :) I am working on a model of an object falling from one layer of air density into another layer with a higher density, effectively changing the acceleration from positive to negative instantly. (Somehow I am thinking of positive...

Homework Statement In the Fig. What should be the initial velocity (magnitude and direction) of the arrow? Also calculate the time of flight. Homework EquationsThe Attempt at a Solution I have formulated 2 equations: v*cos(theta) * t = 20 and 3 = (v * Sin(theta) * t) + (9.81 * t^2)/2 when...

Homework Statement A ball is thrown upward at an angle of 30degrees to the horizontal and lands on the top edge of a building that is 20m away. The top edge is 5.0m above the throwing point. How fast was the ball thrown? Homework Equations x=v0t+(1/2)at2 vf2=V02+2ax vx=v0cosθ vy=v0sinθ The...