Homework Definition and 998 Threads

Homework Statement We fully submerge an irregular 3 kg lump of material in a certain fluid. The fluid that would have been in the space now occupied by the lump has a mass of 2 kg. a) When we release the lump, does it move upward, downward, or remain in place? b) If we next fully submerge it in...

Homework Statement The rain cloud has an approximate volume of 6.50 mile3and an average height, top to bottom, of 350 ft.1 mile = 5280 ft. If a cylindrical container 6 ft in diameter collects 2 in. of water after the rain falls out of the cloud, estimate the total weight of rain that fell from...

Homework Statement If the bulk modulus for water at 70∘F is 319 kip/in^2, determine the change in pressure required to reduce its volume by 0.3%. Homework Equations E = dP/(dV/V) E - Bulk Modulus dP - change in pressure dV - change in volume V - volume The Attempt at a Solution Well I just...

Homework Statement A cord vibrates with a frequency of 3.0 Hz when a mass of 0.60kg is hung up from it. What is its frequency if only 0.38kg hangs from it? Homework Equations f= 1/2pi sqrt k/m The Attempt at a Solution 3.0= 1/2pi sqrt ( k/0.6) k=213.18 N/m f= 1/2pi sqrt (213.18/ 0.38) f=...

Homework Statement I am tasked with finding the theoretical final speed of a car rolling down a hill using energy calculations. I am given the angle of the incline, the height of the ramp, the length of the hill (horizontal and actual length) and the mass of the car. Also, the car is starting...

Homework Statement Charge is distributed on the surface of a spherical balloon (an insulator). A point particle with charge q is inside. If polarization effects are negligible the electrical force on the particle q is greatest when: a. it is near the inside surface of the balloon b. it is at...

I was working on a homework problem today and I got stuck, so I tried manipulating the equation as many different ways as I thought possible hoping that rearranging and substitution would allow me to see something that I was not taking into account. No luck, so then I took a break as is often...

Homework Statement Block A has a mass of 75 kg and is initially at rest on a frictionless inclined plane tilted at a 37 ° above the horizon. Block A is attached to a massless rope that is connected to the top of Block B by way of a massless frictionless pulley. Block B also has a mass of 75 kg...

What is your daily schedule like? How many hours you spend on lectures, and how many hours you spend doing homework? How much do you study during weekends? Do you have "summer-break" like in high school, if so how long? Thank you.

I don't get how to solve this problem in the simplest form... I would appreciate your help thanks! I have had some attempts at the question but the question is supposed to be non-calculator-use, so the method should rather be simple, and I couldn't come up with any sort of neat way to solve the...

Homework Statement Emma and Caleb are playing a game. I don't know what the name is, but they put their fingers together like a hook and then pull. Caleb won. does that mean that Caleb pulls with greater force than Emma pulls him? Caleb wins. Does it mean that he pulls with greater force than...

Homework Statement A uniform, solid sphere of mass 350 grams and radius 25.0 cm has an axle attached to it tangent to its surface. The axle is oriented horizontally, causing the sphere to be suspended below it, its center of mass directly below the axle. Someone lifts the sphere until its...

Homework Statement My professor has given us the solutions to the problem, but I am having a hard time decoding what exactly is going on from the solutions, especially in parts B and C. For Part B: I understand where the numbers are coming from and that this is a force balance problem...

Homework Statement A star cluster contains star HD1, which has an apparent V magnitude of 7.3 mag and a B − V colour of 0.5 mag. Its continuum emission peaks at a wavelength of 557.3 nm, and this star is known to have a bolometric correction of −0.4. (a): Calculate the distance to the star...

A 10.0 kg object is released from the top of an incline with a height of 1.00m. The incline makes a 15.0 degree angle with the horizontal. If the speed of the object is measured to be 3.00m/s at the bottom of the incline, what was the constant frictional force (Fk) along the incline? I have...

Homework Statement If we denote: Alternating current in the primary coil as I1 Alternating current in the secondary coil as I2 Similarly, we denote, Number of turns in primary coil as N1 Number of turns in secondary coil as N2 And, we denote, Voltage generated across primary coil as V1...

Homework Statement For how long you have to let bottle in a river, if you want to cool a liquid inside from 22 °C to 12 °C, when river is 8 °C? Homework Equations Q=cm(T1-T2), Qc=l*S(T-Triver)/d *t The Attempt at a Solution I know how to solve it for a case when we substitute in equation Qc...

Homework Statement Hi all! The problem is - 'find the condition that all roots of $$f(z)=az^3+bz^2+cz+d=0$$ have negative real part, where $$z$$ is a complex number'. The answer - $$a,b,d$$ have the same sign. Homework EquationsThe Attempt at a Solution Honestly, I have no clue about how to...

Good afternoon. You are a student of the career of physical I am 'm like someone aids with the second section (II) the following problem because I do not understand much. Thank you very much. Problem: Considering that the effects of pressure variation with height are due only factor hydrostatic...

Homework Statement We are trying to find out whether we can hit a weight ##m=3## kg up to a given ##h=15.24## meters with a hammer with a head of ##m=6## kg swung at ##v=10## m/s. Homework Equations KE=0.5mv^2 PE=mgh p=mv The Attempt at a Solution One solution is to even see if the energy...

Homework Statement Find the equivalent capacitance of the combination between A and B in the figure. Homework Equations For Equivalent Capacitance in series ##\frac{1}{C}##=##\frac{1}{C_1}##+##\frac{1}{C_2}##For Equivalent Capacitance in parallel ##C##=##C_1##+##C_2##... The Attempt at a...

Homework Statement This is just a general case I'm having trouble trying to imagine: https://lh3.googleusercontent.com/-mTyOwzfLy0E/VluaNlxEddI/AAAAAAAAAEk/2Creguw3xzY/w530-h174-p-rw/Screenshot%2Bfrom%2B2015-11-29%2B21%253A34%253A50.png Suppose there is a cylinder, kind of like a yo-yo, that...

Homework Statement I have to calculate the speed with which a spud gun fires a bullet. The length of barrel is 1 meter. Homework Equations v=s/t , where v=velocity; s=distance; t=time The Attempt at a Solution NOTE: I will easily calculate distance. I have spud gun but I don't know the way...

Homework Statement The figure shows a cord attached to a 2 kg cart that starts from rest and can slide along a frictionless horizontal rail. The right end of the cord is pulled over a frictionless pulley at height h = 2.0 m above the point of attachment of the cord to the mass, so the cart...

Homework Statement What initial mass of 23592U is required to operate a 350 MW reactor for 3 yrs? Assume 46% efficiency. Homework Equations I used Mass* C* efficiency as a decimal= power (e^-6) * time (in seconds) and got 800 as the mass, however, this was incorrect The Attempt at a...

Homework Statement A puck is sliding on flat ground with initial speed to 4 m/s and comes to rest after 2 s. Aprox. which is the coefficent of kinetic friction between puck and ground. 0.9 0.6 0.5 0.4 0.2 I don't know how to solve for this. I ended up in this class accidently and never took...

Homework Statement A helicopter is initially moving at 9 m/s to the left. It then accelerates at 4 m/s^2 to the right for 2s. How far does it travel during the 2 s. answers: 26 m to the right 17m to the right 10m to the left 5 m to the left 1 m to the left If you don't want to give me the...

"Describe an experiment that could be carried out in order to measure the terminal velocity of an object falling under gravity. Include any equations you would use or calculations you would make." The only formula I can think of is F=ma, but I don't see how that is relevent. My train of...

Homework Statement [/B]A 10g bullet accelerates from rest to 500m/s in a gun barrel of length 10cm. Find the accelerating force (assuming it is constant).Homework Equations F=ma, v^2=vo^2+2a(x-xo)? The Attempt at a Solution I tried using F=ma, but it does not equal the answer in the back of...

Homework Statement A tugboat pulls two barges down the river. The barge connected to the tugboat, carrying coal, has an inertia of 2.2 × 105 kg, and the other barge, carrying pig iron, has an inertia of 3.5 × 105 kg.The resistive force between the coal barge and the water is 8.0 × 103 N, and...

Homework Statement How many pairs of solutions make x^4 + px^2 + q = 0 divisable by x^2 + px + q = 0 Homework Equations x1 + x2 = -p x1*x2= q[/B] The Attempt at a Solution I tried making z = x^2 and replacing but got nowhere. I figure 0,1,-1 are 3 numbers that fit but I am not sure what's...

If you fall off of a chair you don't get hurt, however, if you fall off of a building you die. How is this possible if you are experiencing the same force.. F=mg

https://scontent.fdtw1-1.fna.fbcdn.net/hphotos-xat1/v/t35.0-12/12238195_10208423803536754_4071850233616539605_o.jpg?oh=c60d216b6c01a308ff1ace639c0d872f&oe=564A9A62 Here's my attempt at the problem...

Homework Statement A body of mass 35kg moving with velocity Vox=40m/s is subjected to a constant Force of 55N acting in the same direction.How long does it take the speed to increase twice? Homework Equations I would be grateful if anyone could give me hand to solove it after i find the...

Homework Statement Suppose the isosceles prism of the figure(http://imgur.com/EQiQSoO) has apex angle φ = 53.4° and index of refraction n = 1.41. (a) What is the smallest angle of incidence θ for which a ray can enter the left face of the prism and exit the right face? (b) What angle of...

Hello guys! I hope you can give me a hand with this one Homework Statement A satellite consisting of two masses attached by a rigid-massless rod of length L, are orbiting around the Earth at a distance R from the centre of the earth. During the entire movement the rod stays oriented in the...

Hello, I need help with parts 4b-4d and to know if everything I've done is correct.A medical facility is faced with the following information concerning each MRI they provide. Q=2100-.5P MR=4200-4Q TC=400Q+5000 MC=$4001. Find profit maximizing level of output (Q*). Find P at Q*. MR = MC...

Homework Statement In the Circuit(pic attached) the following resistor combination is found. All the resistrs in the figure has resistance R ohms. What is the total resistance across AB? Homework Equations V=IR 3. The attempt at a Solution between point A and B there is only one resistor so i...

So light has momentum: \vec p_{light} If Universal Gravitation tells us: \vec F = \frac{Gm_1m_2}{r^2} How do we get the force on light from the more massive object?... How do we know how much light will be shifted?

If i have an equation: h = ½at2 And: 40 = -4.9t2 → 0 = -4.9t2 - 40 If: v = ∫a then how do i find the velocity given acceleration of -9.8 m/s2?

Using the formulas: s = \frac{1}{2} \alpha t^2 v = \frac{d}{t} a = \frac{v}{t} When we divide distance "s" by time we get velocity: v = \frac{\frac{1}{2} \alpha t^2}{t} = \frac{1}{2} \alpha t When we divide velocity "v" by time we get acceleration: a = \frac{\frac{1}{2} \alpha...

Homework Statement The aim is to find a solution for the scale factor in a Robertson Walker Metric with a scalar field and a Lagrange multiplier. Homework Equations I have this action S=-\frac{1}{2}\int...

Homework Statement [/B] After crossing the patch of soft snow, the skier hits a snowdrift and penetrates a distance 2.1 m into it before coming to a stop. What is the average force exerted on her by the snowdrift as it stops her?Homework Equations TE(initial) = TE(final) The Attempt at a...

Homework Statement Homework Equations T1=T2 The Attempt at a Solution (2Fcos60)L=FL Answer C Is this correct?

Homework Statement A series RLC circuit has R=75 ohms, C=20 mF and a resonance frequency of 5.0 kHz. (i) What is the value of inductance? (ii)What is the impedance of the circuit at residence? (iii)What is the rms current at resonance if the rms voltage of the power supply is 120 V? (iv) How...

Homework Statement A rod extends from a vertical wall at an angle of 27º from the horizontal. A 2.5-kg lamp is mounted at the end of the rod. After John throws his 300-g winter coat over the lamp, what is the magnitude of the tension in the rod? The answers choices are: A) 30N B) 70N C) 27N D)...

Homework Statement Calculate the de - Broglie wavelength associated with a neutron moving with energy of 2ev .( mass of proton mp= 1.67*10^-27 kg ) Homework Equations Wavelength= nh/ 2π KE = eVs = 1/ 2mv^2 eVs=hf Wavelength= v*f The Attempt at a Solution To calculate the wavelength at first...

Homework Statement Hi. I'm in high school physics, and as I'm only 2 months in, I still don't know much. We launched a model rocket as an experiment and I need to find the thrust after adding 100g of mass to the rocket's body. The engine is an Estes A8-3. My teacher told me that its thrust is...

Homework Statement Two identical long wires of radius a = 2.90 mm are parallel and carry identical currents of i = 5.00 A in opposite directions. Their center-to-center separation is W = 17.0 cm. Neglect the flux within the wires but consider the flux in the region between the wires. What is...

Homework Statement A brass rod (linear expansion coef 19*10-6/°C) has a radius of 8139 cm and a copper (linear expansion coef 17*10-6/°C) sheet has a hole or radius 8139+8.86cm. What temperature change (K) is required to close the gap? Homework Equations ΔL/Lo = αΔT? The Attempt at a Solution...