Homework problem Definition and 405 Threads

A 215-g sample of a substance is heated to 330°C and then plunged into a 105-g aluminum calorimeter cup containing 165 g of water and a 17-g glass thermometer at 12.5°C. The final temperature is 35.0°C. What is the specific heat of the substance? (Assume no water boils away.) Please, can...

Homework Statement A ball is tossed from an upper-story window of a building. The ball is given an initial velocity of 8.00m/2 at an angle if 20 degrees below the horizontal. It strikes the ground 3s later. (a) How far horizontally from the base of the building does the ball strike the...

Hi..guys i have question again i guess you gone help me out here is the question 1. A bullet of mass 0.0016 kg moving at 535m/s impacts a large fixed block of wood and travel 5.9 cm before coming to rest. Assuming that the acceleration of the bullet is constant ,find the force exerted by...

Hello! I need to solve this problem proof that sum of kinetic and potentional energy in every part of pendulums(every dot of pendulums swing) swing is equal... Sorry for bad eanglish

Homework Statement I can't seem to understand the steps in solving these types of problems (projectile Motion), and I would like help because I have my first test on Tuesday. A ballplayer standing at homeplate hits a baseball that is caught by another player at the same height above the...

Homework Statement The Attempt at a Solution I don't know how to choose u. I presume we look in 2D; I thought u should look something like: u = \left[ \begin{array}{c} \psi \\ \psi \end{array} \right] and c= \phi but that isn't correct.

A 1000m long and 200m wide (when at rest) spaceship equipped with a chronometer is sent on a roundtrip to their Galactic Base, 8 light years away. (a) Astronauts start the trip after celebrating their captains 29th birthday and they want to make a round trip and return to Earth on the eve of...

Homework Statement Two shooters aim in same target at same time and then the first shooter shots in 70% of the shooting session, and the second is missing in the 60% of the shooting sesion. A. The probability to miss the first shooter is: ______________ B. The probability the target to...

Differentiate the function g(u) = √2u + √3u y = (x^2 - 2√x)/(x) y = (e^x)/(1 + x)

Homework Statement \alpha = 37, m1 = 10 kg Also attachment. Homework Equations The Attempt at a Solution ok, the first question is to find m2 when the system is in rest and the second one is to find the acceleration when m1 = m2. I found 3 equations: n1 = m1 * g * cos(\alpha...

Homework Statement A particle of charge 5.03 nC is placed at the origin of an xy-coordinate system A second particle of charge -2.00 nC is placed on the positive x-axis at x = 4.04 cm. A third particle, of charge 6.01 nC is now placed at the point x = 4.04 cm, y = 3.00 cm. Find...

Homework Statement A prescription for a corrective lens calls for +1.50 diopters. The lensmaker grinds the lens from a "blank" with n = 1.46 and a preformed convex front surface of radius of curvature of 19.0 cm. What should be the radius of curvature of the other surface? Homework...

A raft is constructed of wood having a density of 600.0 kg/m3. The area of its top surface is 5.7 m2, and its volume is 0.50 m3. When the raft is placed in fresh water having a density of 1.0x10^3 kg/m3, how much of it is below water level? What is the upward acceleration of a helium filled...

Homework Statement The Warren County Telephone Company claims in its annual report that “the typical customer spends $60 per month on local and long distance service.” A sample of 12 subscribers revealed the following amounts spent last month. $64 $66 $64 $66 $59 $62 $67 $61 $64 $58 $54...

A 3.30 kg block starts from rest at the top of a 30.0° incline and slides 2.60 m down the incline in 1.50 s. (a) Find the acceleration of the block. 4.9 m/s2 (b) Find the coefficient of kinetic friction between the block and the incline. (c) Find the frictional force acting on the block...

I attached just one question...My tutor and the TA could not figure it out or help me get started on it...can someone help me get started? Thank you so much!

Homework Statement I'm on the last section of identities entitled half angle identities. This one seems to give me some trouble because I have never encountered one with a horizontal shift in it. Tips? tan 1/2( ß + π/2 ) = ( 1 + sin ß ) / cos ß

For which value of k does the matrix A= |4 k| |-7 -5| have one real eigenvalue of multiplicity 2? The Attempt at a Solution - I tried by setting this problem up with det(A-(lambda)I) and trying to solve like that, but I can't seem to get it that way either. I am getting...

Homework Statement a.) a box slides down a 30 degree ramp with an acceleration of 1.20 m/s^2. Determine the kinetic friction between the box and the ramp. Homework Equations The Attempt at a Solution the equation is uk=Fk/Fn but they did not provide me with atleast one force or...

Homework Statement I'd like hints as to how to solve this problem. Thanks! \lim_{x\rightarrow{\inf}}{\frac{x^2-4}{2+x-4x^2}} Homework Equations I think I would begin by dividing out the fraction to get rid of the x^2? Is this the right way to start? The Attempt at a Solution

Homework Statement You adjust your garden hose nozzle for a hard stream of water. You point the nozzle vertically upward at a height of 1.5m above the ground. When you quickly move the nozzle away from the vertical, you hear the water striking the ground next to you for 2.0 s. What is the...

I have this problem on a web assignment due on the 20th of this month. A few of the problems have completely blown my mind including the following: A force F0 causes an acceleration of 18 m/s2 when it acts on an object of mass m sliding on a frictionless surface. Find the magnitude of the...

Homework Statement I have this equation: integrate: dN/(4-2N) Homework Equations The Attempt at a Solution I am understanding that the dN part just goes away and comes one on the top of the fraction. Then on the bottom, I am still left with 4-2N. I am simply saying that it is...

Hi, Homework Statement Find every angle θ between 0 and 360° for which the ratio of sin θ to cos θ is -3.00. (Round your answer to the nearest degree.) Homework Equations The Attempt at a Solution I used the unit circle and took the x value divided by the y value and none of...

Homework Statement y^2 - 2y = x^3 + 2x^2 + 2x + 3 Homework Equations The Attempt at a Solution Solve for y How do you solve for y? my book says since that equation is quadratic in y, it can be solved as y = 1 +- sqrt(x^3 + 2x^2 + 2x + 4) but I have no idea how to do that...

Homework Statement A person jogs eight complete laps around a 400m track in a total time of 13.5 minutes. Calculate, in m/s the average velocity. Homework Equations The Attempt at a Solution I thought that I knew how to do this, but I think I just figured out the average...

In a semiclassical model of the hydrogen atom, the electron orbits the proton at a distance of 0.053nm. What is the electric potential of the proton at the position of the electron? What is the electron's potential energy? (do i use the area on a circle in this equation? or is...

How do I prove that: http://img177.imageshack.us/img177/9184/eqnnq3.th.jpg ?

[SOLVED] Friction Problem Homework Statement A bicyclist can coast down a 5° hill at a constant 8.0 km/h. Assume the force of friction (air resistance) is proportional to the speed v so that Ffr = cv. (a) Calculate the value of the constant c. ________ kg/s (b) What is the...

(a) A swimming pool has dimensions 28.0 m 12.0 m and a flat bottom. When the pool is filled to a depth of 1.90 m with fresh water, what is the force caused by the water on the bottom? (b) What is the force on each end? (The ends are 12.0 m.) (c) What is the force on each side? (The sides are...

Homework Statement Prove that for any n, sqrt n + sqrt (n+1) is irrational. Homework Equations The Attempt at a Solution Well, I know that sqrt 2 + sqrt 3 is irrational. How about sqrt n + sqrt (n+1)? Let sqrt n + sqrt (n+1) be rational. [sqrt n + sqrt (n+1)]^2 = (m^2/n^2)...

This is really not a homework question. I'm learning thermal physics by Schroeder (2000) myself. I'm stuck at Problem 5.17 page 160. I can get Part (a) but Part (b), subtracting off the work that would be required even if the specimen were not present. I subtracted the work...

Homework Statement The function y(x, t) = (15.0 cm) cos(\pix - 12\pit), with x in meters and t in seconds, describes a wave on a taut string. What is the transverse speed for a point on the string at an instant when that point has the displacement y = 12.0 cm? Homework Equations I know...

i was wondering if anyone could help me with this problem i got for homework. I'm not completely sure where to start with this, so any advice is appreciated. the closest problem I've done with this is just finding the angular velocities and accelerations of the other rods, and i don't know if...

[SOLVED] Homework Problem about the Work-Energy Theorem Please help! This is my first year of taking physics and I am really confused... A puck on a shuffleboard decreases in speed from 1.0 m/s to .20 m/s while traveling 4.0 m. What is the coeffecient of kinetic friction between the puck and...

Homework Statement A printed page is to contain 60cm^2 of printed material with clear margins of 5 cm on each and 3 cm on the top and bottom. Find the minimum total area of the page. Homework Equations The Attempt at a Solution I know how to work these questions but am having...

Homework Statement The problem seems like this: on the left, closer to the floor, is block3 with mass 1.0kg, there is a string above it which connects it to block2 with mass 3.0kg which has a string above it that circles around a pulley and comes back down connecting it to block1 with mass...

Homework Statement A 10kg mass is released from rest and slides down an incline that makes an angle of 37degrees with the horizontal. The coefficient of friction is 0.4 on the incline. Determine (a) the force of friction acting to oppose the motion, and (b) the acceleration Homework...

[SOLVED] help with homework problem Homework Statement A uniform disk of radius 4.4 m and mass 9 kg is suspended from a pivot 1.364 m above its center of mass. The acceleration of gravity is 9.8 m/s^2. Find the angular frequency w for small oscillations. The Attempt at a Solution I'm just...

A 1.0 kg magnetized air puck moving across a level table at 0.24 m/s approaches head-on a stationary, similarly magnetized air puck of mass 0.50 kg. If the "magnetic collision" is repulsive and perfectly elastic, determine: (a) the velocity of each puck after the collision (b) the velocity of...

An applied force accelerates mass A at a rate of 6.0m/s^2. The same force applied to mass B accelerates the mass at a rate of 8.0m/s^2. If the same force were used to accelerate both masses together, what would be the resulting acceleration be?

Homework Statement The problem is: After being closed for along time, the switch shown in figure 1 opens at t=0. Find IA for all time. Homework Equations I believe it would be i(t)=Ioe^(-t/(CReq)) or i(t)=(Q/P)+Ae^(-Pt) Q/p=Vo/r and 1/p is time constant or t/(CReq) The Attempt at...

A rectangular solid is to be constructed with a special kind of wire along all the edges. The length of the base is to be twice the width of the base. The height of the rectangular solid is such that the total amount of wire used (for the whole figure) is 40 cm. Find the range of possible...

A projectile is fired from the surface of level ground at an angle Ao above the horizontal. A) Show that the elevation angle B of the highest point as seem from the launch point is related to Ao by tanB = (1/2)tanAo B) Calculate B for Ao = 45 deg So I figure at the highest point, Vy must...

[SOLVED] Pre Calculus Homework Problem...Help! [b]1. Homework Statement A quadrilateral has two pairs of congruent sides and a longer diagonal of length of 6, as shown. For what value of x will the area of the shaded region be 40% of the area of the unshaded region? [b]2. Homework...

Homework Statement A turtle crawls along a straight line, which we will call the x-axis with the positive direction to the right. The equation for the turtle's position as a function of time is x(t)=50.0cm+(2.00cm/s)\,t-(0.0625cm/s^2)t^2 At what time t is the turtle third time a distance...

I have received a homework document from one of my professors. However, I am having difficulty answering some of the questions, since the diagram seems so awful to understand. You can find the document here. http://docs.google.com/Doc?id=dcnj7bph_2fnmnzt For question # 1 and 2 I put...

Homework Statement I've got a problem that I can't figure out. It deals with strain. I've got a box, sitting on the x-y axis(like normal x-y axis's are). The box extends 4 inches from the origin in the x direction, and 2 inches up. Going clockwise(starting at origin) the corners are...

Homework Statement In Figure 5-65, a force of magnitude 13 N is applied to a FedEx box of mass m2 = 1.2 kg. The force is directed up a plane tilted by ? = 38°. The box is connected by a cord to a UPS box of mass m1 = 5.0 kg on the floor. The floor, plane, and pulley are frictionless, and the...

Homework Statement Four point charges are situated at the corners of a square with sides of length a. Find the resultant force on the positive charge q. HINT: write an expression for the resultant force, use Ke for Ke, q for q, and a for a! That makes sense, because not much information is...