Saturday

April 25, 2015

April 25, 2015

**mathematical physics**

For any two vectors u and v show that : ( Vector u.vector v )^2 = [(vector u× vector v)×vector v ].vector u = u^2v^2
*Saturday, March 28, 2015 at 1:43am*

**Physics**

A person pushes on a 56-kg refrigerator with a horizontal force of -260 N; the minus sign indicates that the force points in the -x direction. The coefficient of static friction is 0.58. (a) If the refrigerator does not move, what are the magnitude and direction of the static ...
*Friday, March 27, 2015 at 11:58pm*

**Physics**

At the train station, you notice a large horizontal spring at the end of the track where the train comes in. This is a safety device to stop the train so that it will not plow through the station if the engineer misjudges the stopping distance. While waiting, you wonder what ...
*Friday, March 27, 2015 at 6:33pm*

**Algebra 1**

A physics student stands on top of a hill that has an elevation of 56 meters. He throws a rock and it goes up into the air and then falls past him and lands on the ground below. The path of the rock can be modeled by the equation - y=-0.04x^2+1.3x+56 where x is the horizontal ...
*Friday, March 27, 2015 at 6:12pm*

**mathematical physics**

Obtain the temperature distribution u(x,t) in a laterally insulated rod of length L if both ends on the road are kept at 0°c and the initial temperature distribution in the bar is: u(x,0) = 6sin[πx/L]
*Friday, March 27, 2015 at 1:48pm*

**mathematical physics**

Show that : (I) u = e^xsiny is a solution of Laplace's equation. (ii) u= x^2+t^2 is a solution of the wave equation.
*Friday, March 27, 2015 at 1:36pm*

**mathematical physics**

Solve the initial initial value problem d^2x/dt^2+2DX/dt-3x =0, x(2π) = 0, x(2π) = 13
*Friday, March 27, 2015 at 1:31pm*

**PHYSICS**

A swimmer, capable of swimming at a speed of 1.24 m/s in still water (i.e., the swimmer can swim with a speed of 1.24 m/s relative to the water), starts to swim directly across a 2.24-km-wide river. However, the current is 0.553 m/s, and it carries the swimmer downstream. (a) ...
*Friday, March 27, 2015 at 11:00am*

**physics**

A 2.50m -long, 450g rope pulls a 10.0kg block of ice across a horizontal, frictionless surface. The block accelerates at 2.50m/s2 . How much force pulls forward on the rope?
*Friday, March 27, 2015 at 1:14am*

**Physics **

Cart A has a mass of 10kg and is moving towards cart B at a speed of 15 m/s. If cart B is moving towards cart A with a speed of 5 m/s, what mass must Cart B have to stop both carts upon collision?
*Thursday, March 26, 2015 at 9:29pm*

**Physics**

You drop a rock from a 300-meter cliff. How long will it take to reach the ground? Assume it has no significant air resistance
*Thursday, March 26, 2015 at 9:18pm*

**Physics**

If a ball is launched into the air vertically with a velocity of 20 m/sec, how fast will it be moving after two seconds? (The gravity's acceleration is rounded to 10 m/sec/sec.)
*Thursday, March 26, 2015 at 8:49pm*

**PHYSICS HELP **

Suppose the aliens watching the show are on the surface of Mars. Mass of Mars: 6.42 x 10^23 kg Radius of Mars: 3.394 x 10^6 m Calculate; A) the weight of a 40.0 kg alien on Mars B) the weight of 40.0kg alien on earh Earth-sun distance:1.50x10^11m Mars-sun distance: 2.28 x10^11...
*Thursday, March 26, 2015 at 5:27pm*

**physics**

a force of 150N does 3.40kj of work over a displacement of 25.0m. what is the angle between the force vector and the displacement vector?
*Thursday, March 26, 2015 at 5:18pm*

**physics**

You're in an airplane that flies horizontally with speed 830km/h (230m/s ) when an engine falls off. Neglecting air resistance, assume it takes 35s for the engine to hit the ground. Find the height of airplane. Find the horizontal distance that the aircraft engine falls.
*Thursday, March 26, 2015 at 5:04pm*

**Physics**

It took a force of 262. N to pull a crate weighing 765 N across the floor. The work done was 3500. J. How far was the crate moved?
*Thursday, March 26, 2015 at 5:02pm*

**Physics**

An 78.9 kg person carries a 23 N package up a flight of stairs. The vertical height of the stairs is 23.8 m. How much work is done?
*Thursday, March 26, 2015 at 4:35pm*

**physics 2 AP E&M**

What the flux?
*Thursday, March 26, 2015 at 12:58pm*

**Physics**

A 1500kg car is travelling around a large roundabout of radius 40m at a constant speed of 50kmh-1. Calculate the time it takes to go halfway aound the roundabout. Just wondering which equation I should use. Thanks
*Thursday, March 26, 2015 at 8:31am*

**PHYSICS**

A diver leaves a 3-m board on a trajectory that takes her 2.7m above the board and then into the water 2.9m horizontally from the end of the board.At what speed did she leave the board?At what angle did she leave the board?
*Thursday, March 26, 2015 at 7:21am*

**Physics**

A diver leaves a 3-m board on a trajectory that takes her 2.8m above the board and then into the water 2.7m horizontally from the end of the board.At what speed and angle did she leave the board?
*Thursday, March 26, 2015 at 6:53am*

**Physics**

You can run 8.8m/s,20% faster than your brother. How much head start should you give him in order to have a tie race over 110m?please help:(
*Thursday, March 26, 2015 at 6:52am*

**Physics **

The heating element in a George foreman grill is plugged into a 120-V wall socket, and 1 C of charge passes through it every 0.09 s. What is its power output, and what is the electrical energy being converted into?
*Wednesday, March 25, 2015 at 11:36pm*

**physics**

A penny is dropped from the top of a building 310 m high. Ignoring air resistance, if the penny falls straight down, with what speed would it hit the ground?
*Wednesday, March 25, 2015 at 10:57pm*

**Physics **

A force of 112 N acts on 35 kg box which moves at a steady speed across the floor. The force is directed 40 degrees above the ground. How to state Newton's second law using x components and y components? x: -Fa(cos40) -Ff=ma and y: -Fa(sin40)+Fn-Fg=0? How do you calculate ...
*Wednesday, March 25, 2015 at 9:59pm*

**Physics **

The heating element in a George foreman grill is plugged into a 120-V wall socket, and 1 C of charge passes through it every 0.09 s. What is its power output, and what is the electrical energy being converted into?
*Wednesday, March 25, 2015 at 9:51pm*

**physics**

Two converging lenses are separated by 25.0 cm. The focal length of each lens is 17.0 cm. An object is placed 35.0 cm to the left of the lens that is on the left. Determine the final image distance relative to the lens on the right.
*Wednesday, March 25, 2015 at 9:41pm*

**physics**

Two stones are thrown simultaneously, one straight upward from the base of a cliff and the other straight downward from the top of the cliff. The height of the cliff is 5.28 m. The stones are thrown with the same speed of 9.33 m/s. Find the location (above the base of the ...
*Wednesday, March 25, 2015 at 9:28pm*

**physics**

At an instant when a soccer ball is in contact with the foot of the player kicking it, the horizontal or x component of the ball's acceleration is 930 m/s2 and the vertical or y component of its acceleration is 960 m/s2. The ball's mass is 0.34 kg. What is the ...
*Wednesday, March 25, 2015 at 9:18pm*

**physics**

A fire hose ejects a stream of water at an angle of 31.7 ° above the horizontal. The water leaves the nozzle with a speed of 29.2 m/s. Assuming that the water behaves like a projectile, how far from a building should the fire hose be located to hit the highest possible fire?
*Wednesday, March 25, 2015 at 9:05pm*

**Physics**

In the figure below, a block of mass m = 14 kg is released from rest on a frictionless incline angled of angle θ = 30°. Below the block is a spring that can be compressed 2.0 cm by a force of 270 N. The block momentarily stops when it compresses the spring by 4.6 cm. ...
*Wednesday, March 25, 2015 at 6:13pm*

**physics**

A slab of wood with mass m=1.7kg floats 78% submerged.the density of water is 1000kg/m.what is the density of the wood?
*Wednesday, March 25, 2015 at 12:24pm*

**physics**

A solid ball with a mass m=0.53kg floats in a tank of water.The ball is made of material with a density of 400kg/m^3.The density of water is 1000kg/m^3.what fraction of the ball is below waterline?
*Wednesday, March 25, 2015 at 12:19pm*

**physics**

A fire hose ejects a stream of water at an angle of 31.7 ° above the horizontal. The water leaves the nozzle with a speed of 29.2 m/s. Assuming that the water behaves like a projectile, how far from a building should the fire hose be located to hit the highest possible fire?
*Wednesday, March 25, 2015 at 11:28am*

**physics **

a 20newton object Is pulled along a horizontal surface at a constant velocity by a 30N force. What is the coefficient of friction
*Wednesday, March 25, 2015 at 10:53am*

**physics**

Question Part Points Submissions Used 1 –/2.35 0/100 Total –/2.35 ... Janet wants to find the spring constant of a given spring, so she hangs the spring vertically and attaches a 0.53 kg mass to the spring's other end. If the spring stretches 3.9 cm from its ...
*Wednesday, March 25, 2015 at 8:29am*

**physics**

A mother rocket fired from the ground last year’s eve ejects 25% of its mass 2.0 at the at the rate if so m/s in the first second of its flight. Find the initial acceleration of the mother rocket.
*Wednesday, March 25, 2015 at 6:59am*

**Physics**

A ball is attached to one end of a wire, the other end being fastened to the ceiling. The wire is held horizontal, and the ball is released from rest (see the drawing). It swings downward and strikes a block initially at rest on a horizontal frictionless surface. Air ...
*Wednesday, March 25, 2015 at 6:54am*

**Physics **

A 10kg suitcase is placed on a horizontal conveyor belt the top of which moves to the right. The coefficient of static friction between the belt and box is µs = 0.5 and that of kinetic friction is µk = 0.3. a) Sketch a free body diagram for the suitcase, showing ...
*Wednesday, March 25, 2015 at 6:24am*

**physics**

A mother rocket fired from the ground last year’s eve ejects 25% of its mass at the at the rate if so m/s in the first second of its flight. Find the initial acceleration of the mother rocket.
*Wednesday, March 25, 2015 at 6:10am*

**Physics**

You're an investigator for the National Transportation Safety Board, examining a subway accident in which a train going at 80km/h collided with a slower train traveling in the same direction at 20km/h . Your job is to determine the relative speed of the collision, to help ...
*Wednesday, March 25, 2015 at 2:04am*

**physics**

Starting from home, you bicycle 22km north in 2.3h and then turn around and pedal straight home in 1.3h . What are your (a) displacement at the end of the first 2.3h , (b) average velocity over the first 2.3h , (c) average velocity for the homeward leg of the trip, (d) ...
*Wednesday, March 25, 2015 at 12:53am*

**physics**

Two strings are vibrating at the same frequency of 113 Hz. After the tension in one of the strings is decreased, an observer hears two beats each second when the strings vibrate together. Find the new frequency in the adjusted string.
*Wednesday, March 25, 2015 at 12:39am*

**physics**

A golfer imparts a speed of 25.8 m/s to a ball, and it travels the maximum possible distance before landing on the green. The tee and the green are at the same elevation. (a) How much time does the ball spend in the air? (b) What is the longest "hole in one" that the...
*Wednesday, March 25, 2015 at 12:13am*

**physics**

A tennis ball is struck and departs from the racket horizontally with a speed of 27.7 m/s. The ball hits the court at a horizontal distance of 20.6 m from the racket. How far above the court is the tennis ball when it leaves the racket?
*Wednesday, March 25, 2015 at 12:06am*

**physics**

An object is projected from the surface of the earth with a speed of 2.73x10^4 m/s. What is its speed when it is very far from the earth? (Neglect air resistance).
*Tuesday, March 24, 2015 at 10:36pm*

**Physics**

Calculate the electric force between these two electrons. The value of the Coulomb constant 9 × 109 N · m2/C2 and the elemental charge is 1.6×10−19C. Answer in units of N (Newtons)
*Tuesday, March 24, 2015 at 9:52pm*

**Physics**

There 46.5J of elastic potential energy stored in a spring. How far is the spring stretched if the spring constant is 455N/m
*Tuesday, March 24, 2015 at 9:22pm*

**physics**

One end of a piano wire is wrapped around a cylindrical tuning peg and the other end is fixed in place. The tuning peg is turned so as to stretch the wire. The piano wire is made from steel (Y = 2.0x1011 N/m2). It has a radius of 0.51 mm and an unstrained length of 0.65 m. The...
*Tuesday, March 24, 2015 at 8:01pm*

**physics**

A coin with a diameter of 1.37 cm is dropped on its edge onto a horizontal surface. It starts rolling with an initial angular speed of 10.5 rad/s and rolls in a straight line without slipping. If the rotation slows with an angular deceleration of 2.34 rad/s 2 , how far does ...
*Tuesday, March 24, 2015 at 7:47pm*

**PHYSICS -urgent**

A bomber in level flight, flying at 92m/s, releases a bomb at a height of 1950m. (a) How long is it before the bomb strikes earth? (19.9s) (b) How far does it travel horizontally? (1832m) (c) What are the horizontal and vertical components of its velocity when it strikes? (...
*Tuesday, March 24, 2015 at 7:25pm*

**Physics**

A dragster's top acceleration is 60m/s^2. If it accelerates for 3 seconds from the starting line, how fast will it be going?
*Tuesday, March 24, 2015 at 6:40pm*

**Physics**

The captain of a plane wishes to proceed due west. The cruising speed of the plane is 245 m/s relative to the air. A weather report indicates that a 38.0 m/s wind is blowing from south to north. In what direction should the pilot head the plane relative to the ground?
*Tuesday, March 24, 2015 at 6:35pm*

**Cultural Anthropology**

DESCRIBE 2 REASONS WITH EXAMPLES WHY IT IS IMPORTANT TO HAVE A STRICT CODE OF ETHICS IN ANTHROPOLOGY AND OTHER SOCIAL SCIENCES COMPARED TO MORE SCIENTIFIC DISCLIPLINES SUCH AS CHEMISTRY OR PHYSICS My textbook is Cultural anthroplogy by barbra miller and i can't find ...
*Tuesday, March 24, 2015 at 5:55pm*

**Physics**

Los Angeles (32 degrees North, 119degrees West) and Atlanta (33 degrees North, 84 degrees West) are approximately at the same latitude but not longitude. If a crow were to fly between the two cities what is the approximate shortest flight distance in kilometers?
*Tuesday, March 24, 2015 at 4:43pm*

**physics**

. A long string carries a wave; a 6-m segment of the string contains four complete wavelengths and has a mass of 180 g. The string vibrates sinusoidal with a frequency of 50 Hz and a peak-to-valley displacement of 15 cm. (The “peak-to- valley” distance is the ...
*Tuesday, March 24, 2015 at 3:33pm*

**Physics**

Mass m1 = 0.5 kg moves with constant velocity v1i = 2.5 m/s along the x-axis and collides with mass m2 = 2.6 kg, which moves with velocity v2i = 3.1 m/s, as sketched below(completely vertical). After the collision, m1 and m2 stick together. a.) Find the angle, θ, between ...
*Tuesday, March 24, 2015 at 2:55pm*

**PHYSICS**

A certain resistance thermometer at triple point of water is 152.0 ohms. What is the temperature of the system in degrees celsius when the resistance of the thermometer is 230.51ohms.
*Tuesday, March 24, 2015 at 1:46pm*

**Physics**

A Ferris wheel with a diameter of 35.0 m in starts from rest and achieves its maximum operational tangential speed of 2.20 m/s in a time of 15.0 s. (a) What is the magnitude of the wheel's angular acceleration? (b) What is the magnitude of the tangential acceleration after...
*Tuesday, March 24, 2015 at 12:52pm*

**physics**

a ball was thrown vertically upward from the ground and reaches a height of 50 meters. a) with what speed was it thrown? b) how long will it remain in the air?
*Tuesday, March 24, 2015 at 7:16am*

**physics**

during a scienceday learners use a plastic cold drink bottle as a rocket. they use a bicycle pump to increase the bottle. when the pressure becomes high enough, the bottle is launched vertically upward into the air. the bottle returns to its original position after 3s. ignore ...
*Tuesday, March 24, 2015 at 6:09am*

**Physics**

A 20kg box is being pushed across the floor by a constant force (90,0,0)N. The coefficient of kinetic friction for the table and box is 0.25. At t=5s the box is at location ( 8,2,-1)m, traveling with velocity (3,0,0) m/s. What is the position and velocity at t=5.6s?
*Tuesday, March 24, 2015 at 4:42am*

**physics**

We have to do a lab in physics where we research and write on real life applications of momentum, the guidelines we have are Research Assignment: Application of Momentum in Real-Life Situations Task: Choose any real-life situation where the concept of momentum is involved and ...
*Tuesday, March 24, 2015 at 1:12am*

**physics**

A 5.0 Ω resistor, a 9.0 Ω resistor, and a 12.0 Ω resistor are connected in parallel across a 24.0 V battery. a) What is the equivalent resistance of the circuit? Answer in units of Ω b) What is the current in the 5.0 Ω resistor? Answer in units of A
*Monday, March 23, 2015 at 10:13pm*

**Physics - Electric Field **

Find the electric field at a point midway between 2 charges of +40.0e-9 C and +60.0E-9 C separated by a distance of 30.0 cm. My work: q1=40E-9 q2=60e-9
*Monday, March 23, 2015 at 9:02pm*

**Physics - Electric Fields **

Could someone please explain electric potential energy? Note: The question itself is not on my homework, but I'm having trouble understanding the theory behind my homework.
*Monday, March 23, 2015 at 7:00pm*

**Physics **

A cart is moving at 1.01 m/s to the left has a head-on collision with a 28.5 kg cart traveling 2.04 m/s to the right. If the velocity to the first cart is 2.99 m/s to the right, what is its mass?
*Monday, March 23, 2015 at 6:18pm*

**Physics**

In 2286, Admiral Kirk and his crew were forced to use the slingshot effect in a stolen Klingon Bird-of-Prey to travel back in time to the late 20th century to retrieve two humpback whales. The stolen Klingon Bird-of-Prey traveled towards the sun at a velocity of vs while the ...
*Monday, March 23, 2015 at 5:45pm*

**Physics**

Consider holding a carton of milk in your hand. The force of the bicep muscle actsat an angle of 15 degrees to the vertical, while the weight of the arm and the milk both act downwards. The distance from the elbow to where the bicep muscle is attached via the distal bicep ...
*Monday, March 23, 2015 at 5:44pm*

**physics**

A 1kg block of wood is moving with a velocity of 10 m/s on top of a table. The coefficient of kinetic friction between the block of wood and the table is 0.1. The block of wood is a cube with sides of 12 cm. How far does the block move before coming to a stop? If momentum is ...
*Monday, March 23, 2015 at 5:41pm*

**Physics**

Water flows horizontally in a tapered pipe at a rate of 500 m^3/h. The area at one section of the pipe is 6500 mm² and 4000 mm² at another section. Calculate the gauge pressure at the larger section if the pressure at the smaller section is atmospheric.
*Monday, March 23, 2015 at 4:37pm*

**physics**

A remote control toy car starts from rest and moves with constant unkown acceleration. After half a second it has travel 0.65m. How far has it traveled after 3 seconds?
*Monday, March 23, 2015 at 3:44pm*

**physics**

If 2 objects of unequal masses are hung vertically over a frictionless pulley of negligible mass. determine the magnitude of the acceleration of the two objects and the tension in the light weight cord
*Monday, March 23, 2015 at 3:02pm*

**mathematical physics**

A series circuit consist of a resister with R =200 ohm, an inductor with L=1H, a capacitor with C = 0.002F, and a 12V battery.If the initial charge and current are both 0, find the charge and current at time t.
*Monday, March 23, 2015 at 1:36pm*

**mathematical physics**

Obtain the temperature distribution u( x,t ) in a literally insulated rod of length L if both ends on the rod are kept at 0°c and the initial temperature distribution in the bar is : u(x,0) = 6sin[πx/L]
*Monday, March 23, 2015 at 1:31pm*

**mathematical physics**

Obtain the Fourier for the following periodic function which has a period of 2π : f(x) = [ -1/2 (π-x) for -π<x<0,: 1/2 (π+x) for 0<x<π
*Monday, March 23, 2015 at 1:25pm*

**physics**

Which moves faster after being accelerated from rest, (a) a 500 kg boat that has been imparted with a 10,000 N s impulse or (b) a 780 kg boat imparted with a 14,000 N s impulse?
*Monday, March 23, 2015 at 1:20pm*

**mathematical physics**

Separate the following partial differential equation into a set of three ODEs by the method of separation of variables. d^2/dt^2 = c^2[d^2u/dr^2+1/r du/dr+1/r^2 d^2/d theeta^2]
*Monday, March 23, 2015 at 1:17pm*

**mathematical physics**

Show that :(i) u=e^xsiny is a solution of Laplace's equation. (ii) u= x^2+t^2 is a solution of the wave equation.
*Monday, March 23, 2015 at 1:10pm*

**mathematical physics**

Solve the following ODE using the power series method (1-x^2)y"-2xy'+2y=0
*Monday, March 23, 2015 at 1:06pm*

**mathematical physics**

Calculate the work done by a force Vector F = y^2z^3i^+2xyz^3j^+3xy^2z^2k^ in moving an object along the path defined by the parametric equation x=t, y=t, z=t. Between the point A(t=0) and B(t=1).
*Monday, March 23, 2015 at 8:08am*

**Physics**

Calculate the work done on the system when 1.00 mol of gas held behind a piston expands irriversibly from a volume of 10.0dm^3 against an external pressure of 1.00 bar?
*Monday, March 23, 2015 at 6:44am*

**physics**

A 20.0 kg box slides down a 12.0 m long incline at an angle of 3.0 degrees with the horizontal. A force of 50.0 N is applied to the box to try to pull it up the incline. The applied force makes an angle of 0.00 degrees to the incline. If the incline has a coefficient of ...
*Monday, March 23, 2015 at 6:06am*

**mathematical physics**

Determine the scale factors for an orthogonal coordinate system (s, t, v) whose coordinates are related to the Cartesian by the following equations: x = 2st, y = s^2-t^2, z = v Also write down an expression for the square of the arc element.
*Monday, March 23, 2015 at 5:17am*

**mathematical physics**

Obtain the curl of the following vector field in spherical polar coordinates: vector A = x(xi^+yj^+zk^)
*Monday, March 23, 2015 at 5:12am*

**Physics**

A 4.5-kg brick is suspended by a light string from a 2.0-kg pulley. The brick is released from rest and falls to the floor below. The pulley may be considered a solid disk of radius 1.5 m. What is the linear acceleration of the brick and the tension in the string?
*Monday, March 23, 2015 at 4:40am*

**Physics**

A 180-kg uniform horizontal beam is attached to a vertical wall at one end and is supported by a vertical cable at the other end making an angle of 30 degree above the x axis. What is the magnitude of the tension in the cable?
*Monday, March 23, 2015 at 4:40am*

**Physics**

A uniform plank of length 4.1 m and weight 240 N rests horizontally on two supports, with 1.1 m of the plank hanging over the right support. To what distance x can a person who weighs 445 N walk on the overhanging part of the plank before it just begins to tip?
*Monday, March 23, 2015 at 4:38am*

**Physics**

It takes a force of 53kN on the lead car of a 16-car passenger train with mass 9.1x 10^5 kg to pull it atconstant 45 m/s on level tracks. (a) What power must the locomotive provide to the lead car? (b) How much more power to the lead car than calculated in pan (c) Would be ...
*Monday, March 23, 2015 at 3:30am*

**Physics**

A shopper pushes a grocery cart for a distance 18 m at constant speed on level ground, against a 25 N frictional force. He pushes in a direction 24° below the horizontal. What is the work done on the cart by the shopper, in joules? Magnitude of the force, in newtons, that ...
*Sunday, March 22, 2015 at 10:57pm*

**Physics**

Can someone walk me through how to solve this? Any help is much appreciated! Two masses moving along a straight line undergo a front-to-back collision. The masses are m1= 60.0 kg, with initial velocity v1 = 17.0 m/s, and m2 = 26.0 kg, with initial velocity v2 = 7.0 m/s. After ...
*Sunday, March 22, 2015 at 10:20pm*

**Physics**

A dog, weighing 10.0 lbs, is standing on a flatboat so that he is 20 ft from the shore. He walks 8.0 ft on the boat toward shore and then halts. The boat weighs 40 lb, and one can assume there is no friction between it and the water. How far is he from the shore at the end of ...
*Sunday, March 22, 2015 at 10:14pm*

**Physics**

A 10-g fridge magnet is supposed to hold a 2.0-g paper on the stainless steel fridge door. The normal force of 0.19 N is insufficient to keep them in place, and the paper and magnet accelerate down the fridge at 0.150 m/s2 when the fridge door is slammed. What is the ...
*Sunday, March 22, 2015 at 10:03pm*

**physics**

In a farm yard, a 20.0-kg light is suspended from a light beam on the end of a tall pole. The beam is supported by an arm that attaches to the beam at the suspension point of the light, as shown in the diagram below. The arm makes an angle of 50.0 with the pole. Ignore...
*Sunday, March 22, 2015 at 10:01pm*

**physics**

21.At the airport, a person pushes a luggage cart with an applied force of 150 N [forward]. Assuming the cart and luggage have a total mass of 46.0 kg and the force of friction is 95.0 N [backward], the magnitude of the acceleration of the luggage is _____ m/s2.
*Sunday, March 22, 2015 at 9:57pm*

**Physics **

The position of a mass oscillating on a spring is given by x = (7.0 cm) cos [2πt/(0.71 s)]. (a) What is the frequency of this motion? (b) When is the mass first at the position x = -7.0 cm?
*Sunday, March 22, 2015 at 9:20pm*

**Physics **

A motor boat is traveling at a speed of 2.4 m/s shuts off its engine at t=0. How far does it travel before coming to a rest if it is noted that after 3 seconds its speed has dropped to half of its original value? Assume that the drag force of the water is proportional to v. (R...
*Sunday, March 22, 2015 at 7:04pm*

**Physics **

a car goes over a circular hill of 50m radius at a constant speed of 20m/sec . What is the force of the car on the 600N driver at the top of the hill.?
*Sunday, March 22, 2015 at 7:02pm*

**Physics**

A 51 kg block of metal has specific heat of 222 j/kg c. how heat energy must be applied to the block of metal to raise its temperature from 10 c to 22 c?
*Sunday, March 22, 2015 at 1:44pm*

**physics**

A solid of relative density 1.25 is found to weigh 12g in water find its weight in air
*Sunday, March 22, 2015 at 11:30am*