Initial Definition and 1000 Threads

A basketball player makes a shot from a height of 2.50 m at an angle of 30 degrees above the horizontal. The horizontal distance between the player and the hoop is 6.00 m. The hoop is 3.00m above the ground. Find the magnitude of the initial velocity of the ball which will cause it to go...

I was wondering if it were in actuality possible to assume the universe was created from a big bang, as it seems we used current understanding of the laws of physics as they apply to us now, and extrapolated back. Could it be possible that the boundary conditions we form our laws of physics upon...

Homework Statement I've been given equations that have derivatives as initial conditions, rather than things like u(0,t)=u(L,t)=0 Things like this: http://img444.imageshack.us/img444/5082/mathu.th.jpg Uploaded with ImageShack.us Homework Equations The Attempt at a...

Hi all! I have quiet a lot a problems solving and programing with Mathematica this system of diff. equations: y'[x] == 1/b[x], b'[x] == 1/ubb 1/(y[x] + R1) 1/b[x] (uba 1/(y[x] + R1) - ub), b[0] == b00, y[0] == 0 y[2] == Sqrt[5] where ubb, uba, ub are functions: ub = b[x] -...

A spring gun has a spring with a constant of 2.0 N/cm. If the spring is compressed 3.0cm and the gun is loaded with a .15 kg ball, what will be the initial velocity? Equations such as E(k subscript)=0.5mv^2 E(p subscript)-mgh [b]3. i think that since...

Homework Statement It gives the mass, energy gained (change in energy), initial velocity and power and time I　need to find final velocity Homework Equations EK= 0.5mv^2 The Attempt at a Solution I was thinking of plug in the number into above formula but if i do this i won't be...

Homework Statement This is a 2 part question and I already solved for part I. Part II is what I don't get. a) A 3.16 g object moving to the right at 24.3 cm/s makes an elastic head-on-collision with a 6.32 g object that is initially at rest. The acceleration of gravity is 9.8 m/s2 . 24.3 cm/s...

Homework Statement For the following problem: A piece of balsa wood with density .50 g/cm^3 is released under water. What is its initial acceleration? I have gotten this far: Fnet=Fbuoy-mg -ma=p(water)gV(displaced)- p(wood)g(Vdisplaced) =(p(water)-p(wood))gV=-ma where p="rho" But in this...

Homework Statement A rotation wheel required 3.0 s to complete 37 revolutions. its angular speed at the end of the 3.0 s interval is 98 rad/s. what was the original angular speed of the wheel? Homework Equations average omega = change in angle/change in time The Attempt at a...

Homework Statement Hello I am asked to find the solution to the following equation no infinite series solutions allowed. We are given that there is a string of length 4 with the following... ytt=yxx With y(0,t) = 0 y(4,t) = 0 y(x,0) = 0 yt(x,0) = x from [0,2] and (4-x) from [2,4]. Homework...

Hey everyone; I am a grade 12 student and I am totally stuck on this question and would appreciate your help. I don't want just the answer, I need help with the steps so that I understand how to do this type of problem. Here's the question: A police officer arrives at the...

Hi, we can determine the velocity to hit x and y point with angle of projection given. but can we do the same if the initial height of projection is given?

Homework Statement dy/dx=5y(1-y) y(0)=0.1 x belongs to [0; 2] Homework Equations The Attempt at a Solution dy/5y(1-y)=dx using partial fractions (1/(-y^2+y))=1/(y(1-y))= A/y+B/1-y multiplying both sides by (y(1-y)) gives 1=A(1-y)+B(y) when y=0 1=A so A=1 when y=1...

why doesn't the vertical distance traveled in the given time ,under the action of gravity alone, below the straight line it would follow in the absence of gravity, depend upon the angle of projection of a projectile? With no gravity, the projectile, which is projected at an angle at certain...

1. Homework Statement Two asteroids of 1.0x107kg and 6.0x107kg respectively, are initially at rest in interstellar space separated by a large distance. Thier mutual gravitational attraction then causes then to fall toward each other on a straight line. Assume the asteroids are spheres of...

Homework Statement Someone throws a rubber ball vertically upward from the roof of a building 8.00 m in height. The ball rises, then falls. It misses the edge of the roof, and strikes the ground. If the ball is in the air for 3.00 s, what was its initial velocity? (Disregard air resistance...

I'm reading Roger Penrose's Cycles of Time. On p. 124 he's explaining why he thinks inflation doesn't solve the mystery of why the universe started out in a low-entropy state. He argues that a high-entropy collapsing FLRW universe would consist of "a horrendous mess of congealing black holes,"...

Homework Statement Johnny jumps off a swing, lands sitting down on a grassy 20 degree slope, and slides 3.5m down the slope before stopping. The coefficient of kinetic friction between grass and the seat of Johnny's pants is 0.5 What was his initial speed on the grass?

Homework Statement Y' + 8y = e^-2t*sint, with initial condition y(0) = 0 Homework Equations L{e^(-2t)sin(t)} = 1/((s+2)²+1) The Attempt at a Solution Alright so I've been working on this one for about an hour, I really don't know why but I'm having major problems with these types...

Y' + 8y = e^-2t*sint, with initial condition y(0) = 0 Alright so I've been working on this one for about an hour, I really don't know why but I'm having major problems with these types of problems, whether i don't understand how to set it up or I don't understand partial fraction...

Homework Statement Solve the initial value problem Given: x=0, y=-2Homework Equations 2x(y+1)dx - ydy = 0The Attempt at a Solution Manipulating the given equation: --> 2x(y+1)dx - ydy = 0 --> 2xdx = ydy/(y+1) --> 2xdx = (1 - 1/y+1)dy --> 2x2/2 = y - ln(y+1) + lnC (where lnC is a constant)...

Its been argued that inflation needs the initial conditions to be finely tuned: eg: http://en.wikipedia.org/wiki/Inflation_(cosmology)#Fine-tuning_problem does this paper resolve this problem...

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 3.70 km high so that the rocket, when shot at 37.7° above the horizontal from the very top of the mountain, lands at the foot of the mountain 9.65 km (horizontal distance) away. What initial speed must the rocket have...

Homework Statement An Olympic basketball player shoots towards a basket that is 5.52 m horizontally from her and 3.05 m above the floor. The ball leaves her hand 1.52 m above the floor at an angle of 32.0o above the horizontal. What initial speed should she give the ball so that it reaches the...

Homework Statement Solve: \frac{\partial H}{\partial t} = -4\kappa H^{2} With initial condition: H(0) = 1/L^{2} To find: H(t) = \frac{1}{4\kappa t + L^{2}} 2. The attempt at a solution I tried using Taylor series expansion such that: H(t)\approx H(0)+t\frac{\partial...

Homework Statement Find a continuous y(t) for t > 0 to the initial value prob: y'(t)+p(t)y(t)=0, y(0)=1 where p(t)=2 for 0 < t < 1 p(t)=1 for t > 1 and determine if the soln is unique. The Attempt at a Solution By standard ODE techniques I arrive at y=\exp(-2t) for 0 < t < 1 y=\exp(-t)...

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...

Homework Statement According to the range equation (see below), what angle would give teh maximum range for a given initial velocity? Mathematically explain your hypothesis. Homework Equations The equation given in our book for range: R=(V_{o}cos\Theta)*(2V_{o}sin\Theta)/g...

Homework Statement Exact question: A hobby rocket reaches a height of 35m and lands 259m from the launch point. What was the angle of launch? We know... Xmax = 259m Ymax = 35m Xo and Xmax are at equal y values, or heights, 0 in my chosen coordinate system Homework Equations 1)...

Homework Statement 1. To use Euler midpoint method to find an approx value to y(0.1) using a step size 0.1 2. To use integrating factor method to find exact value of y(0.1) 3. Determine the global error ( min 5 decimal places) Homework Equations f(x,y) = x+y, y(0) = 1.35 The...

Homework Statement Let f(t) be the solution to the initial value problem 2t(dy/dt)+y=t^4 with f(0) = 0 find f(t). Homework Equations The Attempt at a Solution I tried to do this by separating variables but that hasn't gotten me very far. I don't know if I can do it by doing...

Homework Statement A kicker is attempting a field goal from 50 m from the goal posts, which are 3.44 m high. He can kick the ball with initial speeds of 25 m/s. Ignoring air resistance, within what angular range must he kick the ball to score? Homework Equations Pf = Pi + Fnet*t And any...

Homework Statement Compute the initial upward acceleration of a rocket of mass 1.2 multiplied by 10^4 kg if the initial upward force produced by its engine (the thrust) is 2.7 multiplied by 10^5 N. Do not neglect the gravitational force on the rocket. Homework Equations F = ma...

Homework Statement The first stage of a Saturn V space vehicle consumes fuel at the rate of 47400 kg/s, with an exhaust speed of 2820 m/s. The acceleration of gravity is 9.8 m/s2 . Calculate the thrust produced by these en- gines. Answer in units of N. (part 2 of 2) 10.0 points Note...

Hey guys, I was wondering how to find the initial velocity of a ball going up with only the time. The time I have is 3.37, would I use the formula: dy=1/2(a)(t)^2 to find the initial velocity? I got 33.026 m/s but I don't think that's right.

1. Homework Statement For a certain experiment, R-410a vapor is contained in a sealed glass tube at 20°C. It is desired to know the pressure at this condition, but there is no means of measuring it, since the tube is sealed. However, if the tube is cooled to −20°C small droplets of liquid...

Hello Everyone, Is there a list online somewhere of which variable values are 0 and why (conceptually), based on initial conditions? Like I know that for a system at constant volume, w=0. I am looking for a list for the other effects like isothermal, adiabatic, what does pressure= if there is...

Homework Statement A ball is hit from the ground with an angle of 36 degrees above the horizontal. The ball hits a target 30m ahead and 4m above the ground. Find the initial velocity of the ball. Homework Equations Vavg = Δd/Δt aavg = Δv/Δt Δd = voΔt + 1/2aΔt2 The Attempt at a...

Homework Statement haha, so hopefully my last question for the night! Find the initial velocity, when the object is shot at 70 degrees and took 6.5s to land. (hint: look at the y direction first this time) (For more information regarding my question, visit my earlier question from tonight...

Homework Statement An object is shot (from a cannon) at an angle of 33 degrees and landed 85 m away. Calculate the magnitude of the initial velocity (Hint:Look at the x direction and solve for Vox) Homework Equations Other questions I must answer. If you have time, help with these would...

Homework Statement Solve the initial value problem (y+e^-y)y'=sinx subject to y(pi)=0 Homework Equations The Attempt at a Solution I'm not quite sure what to do with this one. I've scanned through my book and could find no similar problems in what we've done so far. I tried to...

Homework Statement To Find initial velocity, given final velocity, and displacement on Y axis. Hello. I've spent four hours trying different solutions to this following problem, none of which have worked. I've just started my undenominated science degree, and since I havn't started lectures...

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...

The problem: The record distance in the sport of throwing compats is 81.1m. This record toss was set by Steve Urner of the US in 1981. Assuming the initial launch angle was 45 degrees and neglecting air resistance, determine a) the initial speed of the projectile and b) the total time the...

Homework Statement 1. A projectile is launched at angle(theta) relative to the horizontal (see the figure below). The initial height of the projectile above the surface of the table is h, and it hits the table at distance (delta)x from the launch point. Find the launch speed vi of the...

Problem: Starting co-ordinates S 45° 50.061 E 170° 27.079 A catapult stationed at the above coordinates will hit the castle, if it shoots at maximum range (X meters) at 48ºtrue. Assume equal initial and final elevation for the projectile’s trajectory, and the projectile’s initial velocity is...

Homework Statement A ball thrown into the air lands on the same horizontal level, 38 m away, and 3 s later. Find the magnitude of the initial velocity. Homework Equations x = vox The Attempt at a Solution I just plugged the x distance which is 38m and the time which is 3s into...

You shoot an arrow into the air. Two seconds later (2.00 ) the arrow has gone straight upward to a height of 25.0 above its launch point What is the initial velocity or the formula I would use to find

Homework Statement An accelerating lab cart passes through two photo gate timers 3.0 m apart in 4.2 s. The velocity of the cart at the second timer is 1.2 m/s (4 marks) a.) What is the cart’s velocity at the first gate? b.) What is the acceleration? Homework Equations v = vi + at Vaverage...