initial speed Definition and 135 Threads

Homework Statement A projectile returns to its original height after 4.08 seconds, during which time it travels 76.2 meters horizontally. If air resistance can be neglected, what was the projectile's initial speed? (Use g = 9.80 .) Homework Equations The Attempt at a Solution...

Two parallel plates are 2.0 cm apart and the electric field strength between them is 1.0 × 10^4 N/C. An electron is launched at a 45 degree angle from the positive plate. What is the maximum initial speed v0 the electron can have without hitting the negative plate? i think the answer is...

Homework Statement A block with mass m = 7.4 kg slides down an inclined plane of slope angle 43.8 ° with a constant velocity. It is then projected up the same plane with an initial speed 3.10 m/s. How far up the incline will the block move before coming to rest? The attempt at a...

Homework Statement A baseball player throws a ball a distance of 250 ft. If the ball is released at an angle of 45°with the horizontal, find its initial speed. Homework Equations The Attempt at a Solution I don't know where to begin. All i know is that speed is the norm of...

For the initial speed of an ideal projectile, how many launch angles equal for the range of the projectile -1 -2 -more than 2 but an infinite number of -only one if the angle is 45 but other wise only 2 -an infinite number

Homework Statement If a flea can jump straight up to a height of .440 m, what is its initial speed as it leaves the ground? How long is it in the air? Homework Equations x = (1/2)at^2+Vo+xo V + at+Vo V^2 = Vo^2+2a(delta x) x-xo = ((Vo-V)/2)t It has to be one of these, since that's...

Driving along a crowded freeway, you notice that it takes a time t to go from one mile marker to the next. When you increase your speed by 4.5 mi/h, the time to go one mile decreases by 9 s. What was your original speed? I've been working on this for 2 hours, I can't seem to get the formula...

Homework Statement A ball ( 2.7 g ) is launched at a 45 degree angle with a solenoid input of 50V. What is the initial speed of the ball? Homework Equations KE = 0.5mv^2 PE = mgh dy = vy(0)t + 0.5at^2 dx = vx(0)t The Attempt at a Solution Voltage is potential energy and I...

Hi First of all, this is not a homework question, but I'm sorry if it's in the wrong sub-forum. I know that a football (soccer) has been kicked a distance of 5 meters using 0,16 seconds, that would give an average speed of 112,5 km/h, or approx 31 m/s. But since the speed of a football is...

Homework Statement A 5000-kg freight car rolls along rails with negligible friction. The car is brought to rest by a combination of two coiled springs as illustrated in the figure below. Both springs are described by Hooke's law and have spring constants with k1 = 1500 N/m and k2 = 3700 N/m...

Homework Statement A body has a constant acceleration of +5 ft/s^2, an initial speed of -10 ft/s, and a time travel of 4 seconds. A)Find the total distance covered B)Find the time at which the body has an instantaneous speed of zero Homework Equations speed=distance/time...

Homework Statement OK, here's the problem: A ball (first ball) is dropped from rest from a height 20.0m above the ground. Another ball is thrown (second ball) vertically upward from the ground at the instant the first ball is released. Determine the intial speed of the second ball if the two...

A ball is launched directly upward from ground level with an initial speed of 18 m/s. (Air resistance is negligible.) What equation would I use to find the time the ball was in the air?

Homework Statement A ball is thrown downward with an initial speed if 20 m/s on earth. What is the acceleration of the ball? Homework Equations vf=a (change in time)t + vi The Attempt at a Solution well you have to find the velocity of then find acceleration. and acceleration is...

The radius of Mercury (from the center to just above the atmosphere) is 2440 km (2440x10^3 m), and its mass is 0.3x10^24 kg. An object is launched straight up from just above the atmosphere of Mercury. (a) What initial speed is needed so that when the object is far from Mercury its final...

Homework Statement A person wants to shoot a rocket off of a mountain 3.26 km high so that the rocket, when shot at 31.3° above the horizontal from the very top of the mountain, lands at the foot of the mountain 9.37 km (horizontal distance) away. What initial speed must the rocket have...

1. A home run is hit such a way that the baseballjust clears a wall 27 m high located 147 mfrom home plate. The ball is hit at an angleof 37◦ to the horizontal, and air resistance isnegligible. Assume the ball is hit at a heightof 1 m above the ground.The acceleration of gravity is 9.8 m/s2...

Homework Statement Help! I have no idea where to begin for this! You are driving along a straight section of roadway (x-axis). You spot a police officer and apply the brakes, slowing down at a constant rate. Your positions (in meters) at successive time intervals of 0.465 s are tabulated...

The world's highest fountain of water is located, appropriately enough, in Fountain Hills, Arizona. The fountain rises to a height of 560 (5 feet higher than the Washington Monument). What is the initial speed of the water

How do u find the initial speed of an object

Hey guys, I'm looking to calculate the initial velocity of a large object sliding to a stop over a surface. This is easy without the drag force of the air, but I'd like to include that to prove a point in my research. As a quick background, I haven't done a differential equation in over a...

Homework Statement An 8.00 g bullet is fired into a 160 g block that is initially at rest at the edge of a table of 1.00 m height. The bullet remains in the block, and after the impact the block lands d = 2.2 m from the bottom of the table. Determine the initial speed of the bullet...

Homework Statement A stone is dropped off a bridge 50m above the water. Exactly 1s later another stone is thrown down and both stones strike the water together. What must the initial speed of the second stone have been? ohh I am sorry but i have no idea please help me out here thank you...

A golf ball is hit and makes a 45o angle with the horizontal as it leaves the tee. It lands 200 m away. What was the ball’s initial speed? I though i know this well but i don't even know how to set this up

What is the longest possible hole-in-one for this golfer? Neglect any distance the ball might roll on the green and assume that the tee and the green are at the same level. in m and: What is the minimum speed of the ball during this hole-in-one shot? please explain your answers :D...

Homework Statement Particle A of mass 1kg is at rest 0.2m from the edge of a smooth horizontal table 0.8m high. It is connected by a light inextensible string of length 0.7m to particle B of mass 0.5kg. Particle B is initially at rest at the edge of table closest to A but then falls out...

Homework Statement Assume acceleration due to gravity is 9.8ms^-2 It has been said that in his youth George Washington threw a silver dollar across a river. Assuming that the river was 75m wide, (a) what minimum initial speed was necessary to get the coin across the river (b) how long was...

A boy tosses a coin straight up to 2.8 m. Suppose the height when the coin leaves his hand is 1.2 m. What was the initial speed of the coin when it left his hand? I'm just confused as to what equation to use. And I don't know whether to assume the acceleration is -9.8 m/s^2. Thanks.

Homework Statement An entertainer juggles balls while doing other activities. In one act, she throws a ball vertically upward, and while it is in the air, she runs to and from a table 5.60 m away at a constant speed of 2.10 m, returning just in time to catch the falling ball. Homework...

Homework Statement A bullet of mass m is fired into a large block of wood, mass M, suspended by two long cords. The bullet comes to rest in the block so that the system swings upwards, coming to rest after traveling through a vertical distance h. Find in terms of m, M, and h: the initial...

Homework Statement Use the equation derived about to calculate the exact value of the initial speed that will produce a circular orbit of the satellite at an altitude of 1000 km above earth.2. Homework Equations -Derived equation provided: Finward = Fg m1 v^2 / r = Gm1m2/r v^2 = Gm2/r v=...

Homework Statement The figure shows a block on a frictionless surface attached to a spring. The block is pulled out to position x_i = 20 cm, then given a "kick" so that it moves to the right with speed v_i. The block then oscillates with an amplitude of 44 cm. Image of the problem -...

Homework Statement A projectile is launched with an intial speed of 60m/s. If it reaches a maximum height of 150m above this level surface then its horizontal range (in m) is ____ ? Homework Equations v^{2} = vo^{2} + 2ay y = yo + Vot + 1/2at^2 The Attempt at a Solution Vo =...

Did I do this right an F=ma need to find Initial Speed? Need help on this. A car whose mass is 2600 kg can produce an unbalanced braking force of 2765N. Calculate the car's initial speed in order to have a stopping distance of 3036.3m. Vi=? So... m=2600kg F=2765N s=3036.3m Vf=0 So I...

Homework Statement A 29.0 g ball is fired horizontally with initial speed v0 toward a 100 g ball that is hanging motionless from a 1.10 m-long string. The balls undergo a head-on, perfectly elastic collision, after which the 100 g ball swings out to a maximum angle θmax = 50.0° see image for...

Homework Statement From a height of 23 m, a ball is thrown horizontally. If it hits the ground with a speed that is three times its initial speed, what is the initial speed? vertical: a = -9.8, x = -23, t = ?, V0=?, V = 3V0 horizontal: ? x is displacement Homework Equations Possibly...

A gun fires a projectile toward a target that is 4.54 km distant at the same elevation as the gun. The gunnery officer notes that the projectile hit the target 27.5 s after firing. a)Find the angle of elevation of the gun barrel. b)Find the initial speed of the projectile. So x=4.54 km...

2586 kg van runs into the back of a 824 kg compact car at rest. They move off together at 8.5 m/s. Assuming the friction with the road can be negligible, find the initial speed of the van. i don't even know where to start :/

Homework Statement blah blah blah Homework Equations momentum = momentum' mv + mv = (m1+m2)v (Uk)N = friction force The Attempt at a Solution It's hard to find how to start with randomly given values. Thank you so much for your help! :D

Homework Statement A ball is thrown with a speed of 70m/s and hits the top of a wall which is 20m tall and 100m away. Find the angle that the ball was thrown at Homework Equations d= V0xt + 1/2 a t^2 a = Vf-V0/t sin^2(theta) = 1 - cos^2 (theta) The Attempt at a Solution I found...

Homework Statement A child runs down a 11 degree hill and then suddenly jumps upward at a 16degree angle above the horizontal and lands 1.2 m down the hill as measured along the hill What was the child's initial speed? Homework Equations Projectile motion x = Vx*t y = yo + Vyo*t -...

Homework Statement A golf ball with an initial angle of 33◦ lands ex- actly 184 m down the range on a level course. The acceleration of gravity is 9.81 m/s2 . a) Neglecting air friction, what initial speed would achieve this result? Answer in units of m/s. 009 (part 2 of 2) 10.0 points...

Homework Statement A rock is thrown from the top of a 20-m high building at an angle of 53 degrees above the horizontal. If the horizontal range of the throw is equal to the height of the building, with what speed was the rock thrown? How long is it in the air? Xf = 20, Xi = 0, Vxi = ?, t =...

Homework Statement While sitting on a tree branch 10.0 m above the ground, you drop a chesnut. When the chestnut has fallen 2.5 m, you throw a second one straight down. What initial speed must you give the 2nd chestnut if they are both to reach the ground at the same time? Other variables...

A projectile launched vertically from the surface of the Moon rises to an altitude of 270 km. What was the projectile's initial speed in m/s? okay so I keep getting this answer wrong but I am pretty sure I am doing it correctly... this is what I am doing: 2*6.67*7.35*270/3.02 and...

Homework Statement A 2.4 mm diameter sphere is charged to -4.4 nC. An electron fired directly at the sphere from far away comes to within 0.31 mm of the surface of the target before being reflected. a) What was the electron's initial speed? b) At what distance from the surface of the...

Homework Statement An archer shoots an arrow horizontally at a target 16m away. The arrow is aimed directly at the center of the target, but it hits 56cm lower. What was the initial speed of the arrow? Homework Equations im not sure of an equation because it does not have t. The...

Homework Statement A batted baseball leaves the bat at an angle of 33.0 above the horizontal and is caught by an outfielder 400 ft from home plate at the same height from which it left the bat What was the initial speed of the ball? How high does the ball rise above the point where it...

Homework Statement A diver springs upward from a board that is 3.05 m above the water. At the instant she contacts the water her speed is 8.51 m/s and her body makes an angle of 75.1 degrees with respect to the horizontal surface of the water. Determine her initial speed as she leaves the...

Homework Statement An object of mass m is suspended from the top of a cart by a string of length L. The cart and object are initially moving to the right at a constant speed vi. The cart comes to rest after colliding and sticking to a bumper, and the suspended object swings through an angle θ...