initial speed Definition and 135 Threads

(a) Find the initial speed. Solution The relevant equations are (4) and (5) derived here and reproduced below as (1) and (2) respectively: $$\begin{align} & \frac{\Delta x}{\tan\!\theta-\tan\!\varphi}=\frac{2v_{0x}^2}{g} \\ & \tan\!\varphi=\frac{1}{2}(\tan\!\theta+\tan\!\omega)...

U1 = -GMm/r K1 = (1/2)mvi^2 U2 = as r approaches infinity, U2 approaches zero K2 = (1/2)mvf^2 (1/2)mvi^2 - GMm/r = (1/2)mvf^2 + 0 vi = √(vf^2 + (2GMm)/r) = √(250,000 + 2(6.7 E-11)(6 E23)/3400) = 153776.815 But that is not the correct answer, can anybody see my mistake/misunderstanding?

In every single question asking about the maximum height you get from jumping in 2 different planets they consider that the speed you leave the ground is constant. Why is that? Speed would be constant if impulse were constant. Impulse would be constant if both force and time were constants...

For this problem, since the weight force on the "particle" (child) is not always aligned with the tangential circular path of the disks, I couldn't think of a way to use rotational kinematics equations. As such, I tried to solve the problem using work principles (namely, that the change in...

Homework Statement In the far future, humans have built a space elevator as a cheap means of access to space. However before that could be done, a few basic principles had to be worked out. . . a) What is the minimum initial speed (in an Earth-centered inertial reference frame) needed for an...

Homework Statement The moving proton hits the second proton, which we consider to be stationary. In the moment of central strike gap between the protons is 10(-13)m. What was the initial speed of the moving proton? Proton mass is 1.67*10(-27)kg and charge 1.6*10(-19) C. Homework Equations...

Homework Statement Homework Equations W =ΔKE The Attempt at a Solution found work done by spring -1.3 =ΔKE -1.3 = KEFINAL - KEINITIAL -1.3 = .5(0.25)(VFINAL2) - .5(0.25)(VINITIAL2) Since v final is 0 since it stops momenteraly at the bottom of the spring -1.3 = - .5(0.25)(VINITIAL2)...

Homework Statement A mass hangs from a light string of length 45cm attached at its other end to the ceiling. If the mass is given an initial speed of 5m/s, what is its speed when it reaches point A in its circular path (see Figure 1)? https://imgur.com/a/ERdlD Homework Equations ##E_i = E_f##...

Homework Statement I have a block on an inclined plane (the angle is 40). The block is projected with an initial speed of 2m/s and μ=0.05. I need to find the time it takes the block to go up the inclined plane and return to the point it started out. Homework EquationsThe Attempt at a Solution...

Homework Statement Consider the system shown to the right. Particles 1 and 2 are fixed in place while particle three is placed at the location shown and released. Let’s look at the mechanics of q3, which has a mass of 3.00 X 10-5 kg. What will be the net force on q3?What will be q3’s...

Homework Statement A 2.0-kg cart collides with a 1.0-kg cart that is initially at rest on a low-friction track. After the collision, the 1.0-kg cart moves to the right at0.50 m/s and the 2.0-kg cart moves to the right at0.30 m/s .If the positive direction is to the right, what was the initial...

Homework Statement Alex Morgan is going to kick a soccer ball into the Canadians goal during the 2015 world cup. Alex kicks the ball straight at the goal from 20.0 m away, and it launches off the ground at an 33.3 degree angle. Assume the goalie is busy faking an injury and ignore air...

Is it possible to solve for the initial speed of projectile hitting a target given that we know the direction (vector) that it is released at and the point on a the surface that it is hitting? If so how would you go about finding an equation to solve for this? I realize that this is a...

Homework Statement An athlete can cover 3.0 m for a standing long jump. Assuming that this athlete jumps at an angle of 45 degrees to the horizontal. calculate the speed at which the jumper can launch herself from a standing start. Assume g =10 ms^-2 and no air resistance Assume that horizontal...

My brother and I were having an argument so I decided to make an account on this forum. Say you were to lurch you hand forward while firing a pistol. Would that affect the max velocity of the bullet?

1. The prIoblem statement, all variables and given/known data You are the chief of the Angry Birds (Google it, if you don’t know the reference...it’s not important). You can shoot red birds from a catapult, and they will fly as projectiles under the effect of gravity. Gravity points downwards...

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 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 = 1700 N/m and k2 = 3000 N/m...

Homework Statement Two charged, parallel, flat conducting surfaces are spaced d = 1.3 cm apart and produce a potential difference ΔV = 625 V between them. An electron is projected from one surface directly toward the second. What is the initial speed of the electron if its comes to rest just at...

Hi, I'm new here and I'm having trouble with a question. 1. Homework Statement A 20.0-kg curling stone is released at the hog line and moves 28.35 m [W] to sit on the button and score a point. If the coefficient of kinetic friction between the stone and the ice is 0.00200, what was the...

If a projectile is thrown at an angle of 60o and it's initial speed is 30m/s, find the maximum height, time used for the ball to reach the ground, the horizontal range the ball reached from starting point, and the final velocity. So can i use 30m/s as the initial velocity?

Homework Statement Estimate the average force exerted by a shot-putter on a 7.0-kg shot if the shot is moved through a distance of 3.0m and is released with a speed of 10m/s . Homework Equations F=ma Maybe the Five Equations for constant acceleration? The Attempt at a Solution So my guess is...

Homework Statement If you want to use a catapult to throw rocks, and the max range is 0.67 km, what initial speed must the rocks have as they leave the catapult?Homework Equations v=Δr/Δt The Attempt at a Solution I sketched a graph of the projectile trajectory with the desired range on the...

Homework Statement Ball A is thrown straight upward and returns to its original level in 2 seconds. Ball B is thrown at a 40 degree angle above the horizontal and also returns to its original level in 2 seconds. What is the initial speed of each ball. Homework Equations ΔV=at...

Homework Statement Hello, An object moves at constant speed in a horizontal surface. Suddenly, a ramp comes along its way. The object starts to climb such ramp. Due to this, the object starts to lose speed. At certain distance, the object loses all of its speed. I want to calculate the value...

It's not homework training problems...I have the answers but I get wrong ans. Homework Statement problem 1 What was the initial speed of a meteorite of mass 1 kg if a total of 18 MJ of thermal and other forms of energy were produced during its fall through the atmosphere of a planet and its...

In a new Olympic event athletes run as fast as they can, jump onto a sled, ride it down a hill and compress a spring as far as they possibly can. (who thinks of these any ways) a. Consider a 55.0 kg athlete that makes it to a top speed of 12.5 m/s before jumping onto a 15.0 kg sled. What is...

Homework Statement a stone is thrown vertically downward from the top of 40 m tall building with an initial speed of 1 after 2s the stone will have traveled a distance of? Homework Equations x=vt+0.5at^2 vf=vi+at The Attempt at a Solution 1(2)+0.5(-9.8)(2)^2=-17.6 the answer i...

Homework Statement A ball thrown vertically from ground level is caught 3.0 s later by a person on a balcony which is 14 m above the ground. Determine the initial speed of the ball. t = 3.0 s, d = 14 m, Vi = ? Homework Equations d = Vi.t + 1/2 a.t^2 The Attempt at a Solution I...

A ball thrown vertically from ground level is caught 3.0 s later by a person on a balcony who is 14 m above the ground, determine the initial speed of the ball. When I first tried doing this problem, I tried using the speed equation of distance/change in time, so I divided 14 by 3 which gave...

Homework Statement A dog jumps a distance, L, and a maximum height, H, where the dog only has horizontal velocity when it travels through the hoop. What is the speed of your dog when he leaves the ground? What is the speed of your dog when he goes through the loop? Both answers should NOT...

A ball is thrown at an unknown speed at an angle of 30 degrees. The initial and final height from the ground is 0 meters. What speed should the ball be launched at in order for it to land on the ground 3 meters from the launch point? Here is what I tried...

Homework Statement So it's a projectile motion problem. I draw a graph showing the parabolic trajectory of the ball, with the start point at the origin. It's final x = 24.8m and final y = 0m Homework Equations We have three constant acceleration equations we use in my course: \vec{v}_{fx}...

Homework Statement The range of a projectile is 483m, and it reached a maximum height of 65m. What were the initial speed and launch angle of the projectile? Assume the start and finish heights are equal. Homework Equations The Attempt at a Solution I just need a push in the...

Homework Statement The question I am struggling with is the second version of a similar problem so to make it easier for me to receive assistance, I'll post both parts: Julie throws a ball to her friend Sarah. The ball leaves Julie's hand a distance 1.5 meters above the ground with an...

I performed a lab where we needed to find the mathematical relationship between the starting speed (initial velocity) and the stopping distance. However, I'm pretty sure we recorded all the initial speeds incorrectly. Is there a way to calculate the initial speed knowing the Distance Traveled...

I have been working this one all day. No luck as far. The question: A projectile is launched at an angle of 53.1° with respect to the horizontal, as shown in Figure 2-34. ( Ill try to give you a picture of example 2-34) It strikes a target that is 120m away horizontally and 160m below the...

Homework Statement So I just wrote my midterm in physics, and I was curious on how to do the last question. Parallel plates, length 5.5cm, Distance between them is 0.3 cm Electric Field (E) is 5.4x10^4 Asking what is the initial speed of a proton going through the parallel plates if it just...

Homework Statement Two balls are thrown vertically upward, one with an initial speed twice that of the other. The ball with the greater initial speed will reach a height - twice that of the other - 4 times that of the other Homework Equations dy = vt + 1/2 at^2 [if i use this equation, i...

According to test performed by the manufactures, an automobile with an initial speed of 75 km/h has a stopping distance of 25 m on a level road. assuming that no skidding occurs during breaking, what is the value of μ , between the wheels and the road required to achieve the stopping distance...

Homework Statement A helium nucleus has radius rHe = 1.9 fm, mass m = 6.6 × 10-27 kg, and charge +2e. A gold nucleus has charge +87e and radius rAu = 7.0 fm. What initial speed must a helium nucleus have if it is to come into contact with a fixed gold nucleus in a head on collision...

Homework Statement An overdamped oscillator with natural frequency w and damping coefficient y starts out at a position xo>0. What is the maximum initial speed (directed toward the origin) it can have and not cross the origin? Homework Equations Overdamped Case Equation...

1. An arrow is shot vertically upward with an initial speed of 25 m/s. When it's exactly halfway to the top of its flight, a second arrow is launched vertically upward from the same spot. The second arrow reaches the first arrow just as the first arrow reaches its highest point. What is the...

In GR a object follows a geodesic when free falling as I understand. A object near the sun for instance wil fall to the sun following that line. If the initial speed is different the path will be different. How can it be that the geadesic is depending on the initial speed of the object...

Car A has twice the mass of Car B but only half as much Ek (Kinetic Energy). When both cars increase their speed by 6.00m/s their resulting Ek's are equal What were the initial speeds of both cars? ANS 1= 4.24m/s ANS 2= 2.12 m/sKe=1/2mV^2 m(a)=2m(b) Ek(a)=1/2Ek(b)...

Acceleration -- all the energy is gravitational what speed was the ball thrown at? Homework Statement A ball is thrown up in the air and reaches a height of 2.2m assuming that all the energy is gravitational what speed was the ball thrown at. Homework Equations I cannot find the...

How can i get an initial speed without acceleration or time?? Homework Statement Hi..heres the problem: A 4WD traveling East has collided with a stationary car, the 4WD's skid marks are 15m long until the point of collision. The 4WD is sent 35degs South for 15.8m and the car is sent...

Homework Statement Hi..heres the problem: A 4WD traveling East has collided with a stationary car, the 4WD's skid marks are 15m long until the point of collision. The 4WD is sent 35degs South for 15.8m and the car is sent 55degs North for 15m. The car has a mass of 1150kg and the 4WD's is...

Homework Statement Find the initial speed (Vo) in Projectile motion in terms of Gravity (g) Height (H) Range (R) Homework Equations Nothing has been given, however, have found these so far... Initial Velocity = sqrt((1/2 * g * R^2)/(cos2θ * (R * tanθ + H)) And a few others which are...

Hi, I'm interresting about the weight of the support of the pendulum with an initial speed. It is the http://en.wikipedia.org/wiki/Pendulum but with an initial speed. The mass come at top with straight initial speed and after turn around the pendulum. I attempt to have the weight of the...