Ball Definition and 999 Threads

I bought one of these plasma globes, decided to do some experiments with it. Since a fluorescent bulb will light up if It's put near the plasma ball, i tried the same with two HID lamps. The Metal Halide shows a very pale white arc, which disappears as soon as the plasma ball is turned off...

Homework Statement A snowball, initially of mass m, slides down a slope inclined at an angle φ with respect to the horizontal. As it moves, the mass of additional snow Δm = αx that it accumulates is proportional to the distance traveled x. Write the differential equation of translational motion...

I graphed different heights from which I had dropped a bouncing rubber ball on the y-axis and the time taken for it to bounce on the x-axis. The function came out to be quadratic, but I do not know why. If someone can show mathematically why this is, that'd be splendid. Thank you.

Homework Statement Two identical conducting balls, b1 and b2, each with a mass of 25.0g both are hanging at 50.0cm at an angle of 45Degrees from the vertical each. Homework Equations Fg = mg Fe = kq/r^2 Ft = ? The Attempt at a Solution I made a free body diagram and am confused on what to do...

Hi all, concerned Dad here - looking for a validating opinion on the following and would be eternally grateful with some guidance/help. The attachment, Unit4ExamAQ7c is from one of my son's honor's exams. He gets #7c CORRECT with the answer v=2.29 m/s. However, the teacher grades him WRONG...

I'm conducting an experiment in order to find the effectiveness of dimples in a golf ball when flying through the air. As part of the experiment, I'm planning on testing the different dimple patterns of various golf balls. However, I'm having trouble coming up with a numerical ratio that can...

1. Assume there is gravity and no external force acting on the system. A ball has an initial velocity of 5 m/s and climbs up a parabolic ramp, which is defined by y=(x^2)/3. If the ball rolls exactly along the path of ramp and energy of the ball is conserved, starting from (0,0), calculate the...

Homework Statement The image above shows a basketball (a thin spherical shell I=⅔ mR^2) rolling don an incline of height 8.4 m. If the ball is already rolling with an initial linear speed of 3.0 m/s then what will be the final linear speed when it rolls off the incline? Homework Equations I =...

Homework Statement Does anyone know how to plot a displacement-time graph that will give the average velocity of a bouncing ball? The ball bounces 5 times and I would like to know it's average velocity. What equations would I use? Homework Equations 0.5mv^2=mgh? The Attempt at a Solution I...

Homework Statement Two balls collide in a perfectly elastic collision. Ball 1 has a mass of 3.5kg and is initially traveling at a velocity of 5.4m/s. It collides head-on with stationary ball 2 with mass 4.8kg. Determine the final velocity of ball 2. Given: m1=3.5kg vi1=5.4m/s m2=4.8kg...

Homework Statement Two identical balls A and B are dropped from rest into a tall column of viscous liquid. Ball A is dropped from the surface of the liquid while ball B is dropped from a small height ##h## above the liquid. Let ##E_A## and ##E_B## be the loss in mechanical energy of bal A and B...

Homework Statement I'm trying to come up with an equation to determine where a ball would land (basically the distance it moves) from a spring loaded projectile launcher set up on a table. I'm looking for "d", and I know the spring constant, compression, mass of the ball, height the ball starts...

Homework Statement So I have to do a report about tennis and about the spin. I understand how the magnus effect works and how the ball will bounce but am still unable to figure out how the actual spin is created by the contact with the racquet and the moving ball Homework Equations T=Fr The...

Homework Statement I need to find the velocity vector of the cue ball. I know the start-coordinates, end-coordinates(when it hits the red ball), and the time it takes for the travel, but i have no clue on how to make the vector. start(21, 0) end(21, 12) time = 0.1seconds not sure if...

Homework Statement How to find deceleration of a ball that is hit, given the ball: mass=0.1kg F=20N is hit by a bat for 0.01s has an acceleration of 200ms^-2 when hit by bat speed=2m per sec travels 0.01m as it is being hit by the bat Was initially at rest.Homework Equations a=(v-u)/t The...

Homework Statement A ball is thrown 2.8m/s vertically upward from a window that is 3.6m above the ground. calculate the amount of time the ball spends in the air. Homework Equations quadratic equation d = Vi(t) + 1/2(a)(t)2 The Attempt at a Solution d = Vi(t) + 1/2(a)(t)2 3.6m =2.8...

Homework Statement http://imgur.com/0t8TVgq http://imgur.com/0t8TVgq [Image copy inserted by moderator] Sorry about all the erase marks. My question is why is the final velocity not 0. Homework Equations V=Vo+at[/B] The Attempt at a Solution So the question is asking for the horizontal...

I have a physics homework question that i need help with; A submerged ball of negligible mass is attached to the bottom of a swimming pool by two strings as shown. The volume of the ball is 5000cm^3. Calculate the tension in each string. (hint you need to look up the density of water) How do i...

Homework Statement Show that ##\overline{B(a,r)} = \{ x \in \mathbf R^n ; |a-x| \le r \}## in ##\mathbf R^n## for all points ##a \in \mathbf R^n## and ##r>0##. Is it possible to generalize the statement to any normed vector space? Give a example of a metric space where the statement is not...

Homework Statement A 150 gram ball slides down a smooth track with no friction, which has a circular loop with radius 20 centimeters. The ball has an initial speed of 3 m/s. Its initial position is 80 centimeters above the lowest point of the circular loop. Calculate the normal force of the...

Homework Statement Ball of mass m and radius r rolls without sliding in a bowl of radius R. Express it's angular velocity ω as a function of the angle θ. What are the normal force and friction force as a function of θ. Homework Equations Moment of inertia of a solid ball round it's center...

So if a ball is rolling down a ramp and not slipping, you have two torques... the mg*sin(theta) portion of gravity and the (mu)mgcos(theta) for friction. My question is this: Does this friction force remove energy from the ball? (I know it affects the balls rotation but this is just changing...

Could anyone please recommend any papers that describe the path of a 4D ball through 3D space?

Homework Statement Suppose we drop a lead ball of mass M into water of mass m from a height h and allow everything to settle down. What is the temperature change of the water? Assume that the container is well insulated. Homework Equations Potential Energy = mgh dU = mcdT where dU is the...

Homework Statement A bowler throws a bowling ball of radius R = 11 cm along a lane. The ball (the figure) slides on the lane with initial speed vcom,0 = 7.8 m/s and initial angular speed ω0 = 0. The coefficient of kinetic friction between the ball and the lane is 0.13. The kinetic frictional...

Homework Statement "Take a tennis ball and cut it into 2 equal halves. Take one of them and cut it again equally. You now have 1 half tennis ball and 2 quarter tennis balls. Glue the 2 quarters to the half, one to its outside (convex) and one to its inside (concave). Design, build and test a...

Homework Statement A 0.060 kg tennis ball, moving with a speed of 2.50 m/s has a head on collision with a 0.090 kg ball initially moving toward it with a speed of 1.00 m/s. Assuming a perfectly elastic collision, what is the speed and direction of each ball after the collision? Homework...

A rubber ball is bouncing on a flat surface. Every time it bounces, it loses energy, while the sound of the ball hitting the surface accelerates (because the intervals of the ball impacting the surface become shorter with each bounce). The ball seems to be accelerating when, in fact, it is...

Homework Statement A tennis ball has a mass of 75 g that is placed above a basketball has a mass of 590 g. Both are stationary and They were dropped from a height about 1.2 m ( The collisions are perfectly elastic) 1) Calculate the speed of the basketball when it reaches the ground 2) Calculate...

Hi folks! I am looking for a ball bearing assembly that can be easily taken apart and re-assembled. I'm trying to test some ball bearings (the balls themselves) so its advantageous to have a housing that I can easily take apart and reload with a different type of ball without damaging anything...

Homework Statement Two students are on a balcony a distance h above the S street. One student throws a ball vertically downward at a speed vi ; at the same time, the other student throws a ball vertically upward at the same speed. Answer the following symbolically in terms of vi, g, h, and t...

As the name of the thread says, I am wondering what would the amount and the direction of the electric field at some point in the uniformly charged ball of radius R(it has a constant charge volume density) be at the distance r from the centre of the ball. Does anyone know what would they be? I...

Homework Statement A bowling ball is released with speed V and no rotational kinetic energy. After a period of sliding and rotating, the ball enters pure rotational motion. The coefficient of friction between the ball and the ground while sliding is Uk. a. Show that the rotational acceleration...

I am doing a lab in my senior physics class (IB HL Physics 3-4) and I am very confused about a relationship that I found. For my experiment I dropped a racquetball from different heights and then used video analysis to find the height of the ball on its final bounce. I used this data to...

Homework Statement A 3.50 kg ball with a velocity of 10.00 m/s collides with a stationary ball with a mass of 5.00 kg. After the collision, the first ball travels at a 42.6 degree angle from its original path, while the second ball travels at a -26.7 degree angle from the other ball's original...

Homework Statement The classic double ball drop question: a ball of mass m is placed directly above another ball of mass M, and assume that m is not negligible. Both balls are dropped simultaneously. Find the mass m such that, upon the second collision (m with M), M has a final velocity of...

A ball of mass 15.47kg rests on a table of height 0.73m. The tabletop is rectangular with a mass of 12.11kg, supported by 4 thin legs. The width of it is 134.0cm and length of 63.7cm. If the ball touches the tabletop at point (67.0cm, 16.4cm) relative to corner 1, what is the force the tabletop...

Homework Statement A 3.50 kg ball with a velocity of 10.00 m/s collides with a stationary ball with a mass of 5.00 kg. After the collision, the first ball travels at a 42.6 degree angle from its original path, while the second ball travels at a -26.7 degree angle from the other ball's original...

International basked ball games are played with a basket ball inflated to 8 PSI. But I am curious to understand how it can stay inflated when the atmospheric pressure is 14.7 PSI. So shouldn't the external atmospheric pressure overcome the pressure within the ball ? Shouldn't the air pressure...

Homework Statement Hi everybody! Here is a classical mechanics problem about a ball (mass m, radius r) rolling down a slope (from height h) and going through a loop-the-loop. a) What is the minimum height h from which the ball must roll in order to successfully complete the loop-the-loop...

I'm trying to figure out a way to get better results in a "pumpkin launching" contest. The goal is to launch an 8-12 lb pumpkin (or bowling ball) as far as possible.One method is going to use elastic, bungee or large rubber/latex bands as the method of propulsion. The problem is there are...

I got this probability question as homework, but I got very confused as I didn't know if I should calculate the balls in the 2 boxes as whole or if I should calculate the probability of the first box then add the probability of the second. Any help is appreciated. Thanks.Here is the question...

Homework Statement A 0.5 kg ball is swung in a circular path from a 80 cm long rope, attached to a vertical pole. A. What is the speed of the ball theta (between the pole and rope) is 40 deg? B. What is the KE of the ball at theta = 40 deg? C. The ball slows down and the KE drops to 50% of the...

Homework Statement This is a Lab: A Ball is placed on a 14cm high ramp and it rolls down to the bottom of the ramp and onto a table where it rolls 20cm (the ramp's horizontal displacement is 16.5cm). After rolling on the table, the ball falls off the table for 76.5cm with a forward horizontal...

Homework Statement Part 1: I've worked out part 1 already. The answer is 4650m/s^2 A ball travels vertically downwards until it hits a concrete floor with speed 22.7-m/s. It then bounces vertically upwards at 10.8-m/s. Examination of a high speed video shows that the collision took 7.2-ms...

Homework Statement At the instant illustrated, which best describes the angular momentum of the ball and net torque on the ball, as measured around the origin? L⃗ is in the kˆ direction, ⃗τ is 0. Homework Equations torque= (F)x(r) Tension in rope= (mv^2/r)+qvbThe Attempt at a Solution I am...

Homework Statement Imagine a ball with moment of inertia I_{cm} = \beta MR^2 encountering a circular loop of radius R_0 > R after rolling on a level surface at a speed of v_0. Assume that the ball does not slip. Attached a diagram. A) What is the minimum value of v_0 required for the ball...

Homework Statement If the density of the half-ball x ^2 + y ^2 + z ^2 ≤ 4 ; z ≥ 0 is given by δ(x, y, z) = ( x^ 2 + y^ 2 + z ^2)^(1/2) find its mass. Homework Equations ∫∫F⋅ds ∫∫FoΦ(u,v)||Tu,Tv||dudv ∫∫FoΦ(u,v)⋅(Tu,Tv)dudvThe Attempt at a Solution For the last problem I was asked to find the...

The great Ben Hogan said he learned from a physics book when he was on the PGA Tour that if the golf club head is still accelerating AFTER it has struck the golf ball, the result is a straighter shot on line to the target. I can't find any examples of what he is talking about in the physics...

Homework Statement "In a jump spike, a volleyball player slams the ball from overhead and toward the opposite floor. Controlling the angle of the spike is difficult. Suppose a ball is spiked from a height of 2.30 m with an initial speed of 20.0 m/s at a downward angle of 18.00°. How much...