Monday

July 28, 2014

July 28, 2014

**Recent Homework Questions About Physics**

Post a New Question | Current Questions

**Physics**

Help me with this question, please How will the total voltage of a string of light bulbs in series change as you add more bulbs to the string? A. The total voltage will decrease B. The total voltage will stay the same C. The total voltage will increase d. You cannot predict ...
*Tuesday, June 3, 2014 at 4:13pm*

**physics **

A pilot is flying from City A to City B which is 300 km [NW]. If the plane will encounter a constant wind of 80 km/h from the north and the schedule insists that he complete his trip in 0.75 h, what air speed and heading should the plane have?
*Tuesday, June 3, 2014 at 4:02pm*

**physics**

A passenger on a train notices that a 2.00 kg mass is displaced 10.0° from the vertical as the train accelerates. (a) What is the acceleration of the train? (b) What would the acceleration be if the mass was 5.00 kg? c. What would angle have to be to indicate a horizontal ...
*Tuesday, June 3, 2014 at 3:17pm*

**Physics**

A 15.0 kΩ resistor is hooked up to a 45.0 V battery in a circuit with a switch. a.) What is the current flowing through the resistor? b.) What is the power dissipated by the resistor?
*Tuesday, June 3, 2014 at 3:16pm*

**Physics**

I know this is long but can someone just explain it to me? Please? Don't have to give the answer, I'm just confused :( 1. An experiment was devised to investigate the effects on the temperature of a cup of hot tea when lemon juice is added at different time intervals. ...
*Tuesday, June 3, 2014 at 2:21pm*

**Physics**

Consider the 52.0-kg mountain climber in the figure to the right. Find (a) the tension in the rope and (b) the force that the mountain climber must exert with her feet on the vertical rock face to remain stationary. Assume that the force is exerted parallel to her legs. Also, ...
*Tuesday, June 3, 2014 at 12:12pm*

**Physics**

Calculate the maximum deceleration of a car that is heading down a 30.0° slope (one that makes an angle of 30° with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires and that the ...
*Tuesday, June 3, 2014 at 12:12pm*

**Physics**

A passenger on a train notices that a 2.00 kg mass is displaced 10.0° from the vertical as the train accelerates. (a) What is the acceleration of the train? (b) What would the acceleration be if the mass was 5.00 kg? c. What would angle have to be to indicate a horizontal ...
*Tuesday, June 3, 2014 at 12:11pm*

**Physics**

A 10.0N frictionless pulley is suspended from an overhead supported by a chain. two weights suspend off the pulley. One weight is 30.0N and the other is 20.0N. (a) What is the tension on the rope? (B) what is the acceleration of the weights? (c) what is the tension on the chain?
*Tuesday, June 3, 2014 at 12:09pm*

**Physics**

Q1:Find the phase and group velocities of the de Broglie waves of an electron whose kinetic energy is 500kev?
*Tuesday, June 3, 2014 at 8:48am*

**Physics**

A wind turbine has blades that sweep an area of 2000m2. It converts the power available in the wind to electrical power with an efficiency of 50%. What is the electrical power generated if the wind speed is 10ms–1? (The density of air is 1.3 kg m–3.)
*Tuesday, June 3, 2014 at 4:03am*

**Physics**

Q1: Find the frequency of revolution of the electron in the classical model of the hydrogen atom.In what region of the spectrum are electromagnetic waves of this frequency?? Q2:A beam of 13.o electrons is used to bombared gaseous hydrogen.What series of wavelengths will be ...
*Tuesday, June 3, 2014 at 3:36am*

**physics**

two identical copper spheres are separated by 1m in vacuum. how many electrons would have to be removed from one sphere and added to other sphere so that they attract each other with force of 0.9N
*Monday, June 2, 2014 at 11:44pm*

**Physics HELP ME PLEASE**

A 1250 kg car increases it's speed from 11 m/s to 27 m/s in 5.4 s. - What is the cars acceleration? - How much force is required?
*Monday, June 2, 2014 at 10:51pm*

**physics**

An astronaut on Triton throws a 0.142 kg baseball straight up with a velocity of 24 m/s. How high does the baseball go?
*Monday, June 2, 2014 at 10:40pm*

**physics**

A 280 N block rests on a 30° incline. (a) What is the normal force exerted by the incline on the block? (b) What (static) friction force is needed to prevent the block from sliding down the incline? (c) What is the minimum coefficient of static friction needed?
*Monday, June 2, 2014 at 9:07pm*

**Physics I NEED HELP BADLY**

An airplane traveling east at a speed of 270 km/h encounters a wind of 75 km/h what is the resulting speed of the plane if: - The wind is blowing east. - The wind is blowing west. - The wind is blowing north. ************* CLICK ON MY NAME TO SEE IF YOU CAN HELP ME WITH ANY ...
*Monday, June 2, 2014 at 6:37pm*

**Physics**

A 10.0N frictionless pulley is suspended from an overhead supported by a chain. two weights suspend off the pulley. One weight is 30.0N and the other is 20.0N. (a) What is the tension on the rope? (B) what is the acceleration of the weights? (c) what is the tension on the chain?
*Monday, June 2, 2014 at 6:29pm*

**physics**

A acorn falls from a tree and hits the ground with a speed of 10 m/s: - From what height did the acorn fall? - How long was the acorn in the air?
*Monday, June 2, 2014 at 6:29pm*

**Physics**

A car drives off a 20 m bridge at 35 m/s. Find the distance from the base of the bridge to when the car will land. (2 part question)
*Monday, June 2, 2014 at 6:27pm*

**Physics**

The velocity of a wave on a particular string is 21.8 m/s and the string is 3 meters long. What are the 3 lowest harmonic frequencies that with produce a standing wave?
*Monday, June 2, 2014 at 6:25pm*

**Physics**

20 wave crests pass a fisherman in one minute if the wave crests are 2.0 m apart find: Period Frequency Speed of waves
*Monday, June 2, 2014 at 6:22pm*

**physics**

two objects of equal mass are placed in a room. Object A is placed on the floor and object B is placed on a table top that is 3 meters of the ground. Which one has more potential energy and why?
*Monday, June 2, 2014 at 4:47pm*

**Physics **

A 50 g ball of clay traveling at speed v0 hits and sticks to a 1.0 kg block sitting at rest on a frictionless surface. A) What is the speed of the block after the collision? B) What percentage of the ball's initial energy is "lost"?
*Monday, June 2, 2014 at 3:25pm*

**Physics **

A) What is the kinetic energy of a 1200kg car traveling at a speed of 30 m/s (≈65mph)? B) From what height would the car have to be dropped to have this same amount of kinetic energy just before impact?
*Monday, June 2, 2014 at 3:24pm*

**physics**

A particle moves along the x-axis from an initial position xi to a final position xf. Of the following values of xi and xf, which results in a negative displacement? (a) xi = 6 m, xf = 4 m (b) xi = ?4 m, xf = ?2 m (c) xi = ?4 m, xf = 2 m (d) xi = 4 m, xf = 6 m (e) xi = ?4 m, ...
*Monday, June 2, 2014 at 3:06pm*

**physics**

You are going for a bike ride. You ride down a straight road at a speed of 9.0 mi/hr. Just as you pass the point which is 3.6 miles from your starting point, you develop a flat tire. You get off your bike and walk it to a bike shop 0.5 miles further down the road. The walk to ...
*Monday, June 2, 2014 at 2:12pm*

**Physics**

A 10.0 Ω resistor is hooked up in series with an 8.0 Ω resistor followed by a 27.0 Ω resistor. The circuit is powered by a 9.0 V battery -Calculate the equivalent resistance. -Calculate the voltage drop across each resistor in the circuit.
*Monday, June 2, 2014 at 1:43pm*

**physics**

What is the free-fall acceleration in a location where the period of a 2.87 m long pendulum is 3.4 s? Answer in units of m/s 2
*Monday, June 2, 2014 at 1:08pm*

**Physics**

A rock is thrown vertically up into the air. It reaches a maximum height 15m above point where it was released. What is its initial velocity? a) 17 m/s b) 26 m/s c) 14 m/s d) 20 m/s I know the answer is a) 17 m/s and I got it wrong thinking it was d) 20 m/s but I can't ...
*Monday, June 2, 2014 at 10:44am*

**physics**

a body of weight 10 n is kept on a smooth horizontal table.what is the force exerted on the table by the body
*Monday, June 2, 2014 at 1:19am*

**physics**

A senior citizen walks 275 m in 25 min going around a shopping mall. If she wants to increase her average speed by 25 % in walking a second lap, what would her travel time in minutes have to be?
*Sunday, June 1, 2014 at 11:36pm*

**physics**

A car is rounding a circular curve of radius r on a banked turn. As the drawing indicates, there are two forces acting on the car, its weight mg and the normal force FN exerted on it by the road. Which force, or force component, provides the centripetal force that keeps the ...
*Sunday, June 1, 2014 at 10:42pm*

**physics**

A car is rounding a circular curve of radius r on a banked turn. As the drawing indicates, there are two forces acting on the car, its weight mg and the normal force FN exerted on it by the road. Which force, or force component, provides the centripetal force that keeps the ...
*Sunday, June 1, 2014 at 10:39pm*

**Physics **

A) What is the kinetic energy of a 1200kg car traveling at a speed of 30 m/s (≈65mph)? B) From what height would the car have to be dropped to have this same amount of kinetic energy just before impact?
*Sunday, June 1, 2014 at 10:39pm*

**Physics**

A 1 kg hockey puck is sliding on the ice at 5m/s and stops on some dirt in 2 secs. I need to find the coefficient of kinetic friction. I found the acceleration being -2.5m/s^s (0-5m/s / 2s) Idk what to do next pleaseeee help
*Sunday, June 1, 2014 at 10:18pm*

**Physics (electricity and Magnetism)**

A long straight and thin wire has a charge Q per unit length. It is also carrying a current I. A point charge is moving with a velocity v parallel to the conductor, at a distance d from it. Find the velocity v, supposing a correct direction for the current and the current ...
*Sunday, June 1, 2014 at 8:37pm*

**physics**

A 68.0 kg ice skater moving to the right with a velocity of 2.55 m/s throws a 0.16 kg snowball to the right with a velocity of 27.5 m/s relative to the ground. (a) What is the velocity of the ice skater after throwing the snowball? Disregard the friction between the skates and...
*Sunday, June 1, 2014 at 6:22pm*

**physics**

A clerk moves a box of cans down an aisle by pulling on a strap attached to the box. The clerk pulls with a force of 173.0 N at an angle of 31° with the horizontal. The box has a mass of 40 kg, and the coefficient of kinetic friction between the box and the floor is 0.45. ...
*Sunday, June 1, 2014 at 1:07pm*

**Physics **

Two blocks A and B are connected by a light in extensible cord passing over a frictionless pulley. Block A starts from rest and moves up the smooth plane which is inclined at 30 degrees to the horizontal. Calculate at the moment that A has moved 4 m along the plane. (a) the ...
*Sunday, June 1, 2014 at 7:03am*

**Physics**

After undergoing through 90 degree compton scattering, the fraction of energy lost by photon is A) 10 % B) 50 % C) 20 % D) Zero E) None
*Sunday, June 1, 2014 at 6:28am*

**Physics**

A shell is fired from the ground with an initial speed of 1.54 ✕ 103 m/s at an initial angle of 52° to the horizontal. (a) Neglecting air resistance, find the shell's horizontal range. (b) Find the amount of time the shell is in motion.
*Saturday, May 31, 2014 at 11:31pm*

**physics**

Consider a pulse of laser light aimed at the Moon that bounces back to Earth. The distance between Earth and the Moon is 3.84 * 108 m. Show that the round-trip time for the light is 2.56 s.
*Saturday, May 31, 2014 at 9:27pm*

**physics**

A 3 kg object traveling 6m/s east has a perfectly elastic collilsion with a 4kg object traveling 8 m/s west After the sollision, the 3 kg object will travel 10 m/s west a. What was the total momentum before the collision? b. What is the total momentum of these objects after ...
*Saturday, May 31, 2014 at 6:26pm*

**Physics.**

A 500 g block lies on a horizontal tabletop. The coefficient of kinetic friction between the block and the surface is 0.25. The block is connected by a massless string to the second block with a mass of 300 g. The string passes over a light frictionless pulley as shown above. ...
*Saturday, May 31, 2014 at 4:34pm*

**Physics**

Please Help I have no idea how to approach this problem In a "Rotor-ride" at a carnival, people rotate in a vertical cylindrically walled "room." If the room radius was 5.7m , and the rotation frequency 0.35 revolutions per second when the floor drops out, ...
*Saturday, May 31, 2014 at 4:24pm*

**physics**

7. The speed of a man with and against the water currents in a river are 15km/h and 5km/h respectively. Find his speed in still water and the speed of the water currents.
*Saturday, May 31, 2014 at 6:13am*

**physics**

6. Two particles are moving with a constant speed v such that these are always at a constant distance d apart and their velocities are equal and opposite. After what time do these return to their original positions
*Saturday, May 31, 2014 at 5:52am*

**physics**

A stone is projected vertically to reach a maximum height 'h'. The ratio of kinetic energy to potential energy at a height 4h/5 is 1) 5:4 2) 4:5 3) 1:4 4) 4:1
*Saturday, May 31, 2014 at 2:04am*

**Physics**

A solid rubber ball has a diameter of 8.0 cm. It is released from rest with the top of the ball 80 cm above a horizontal surface. It falls vertically and then bounces back up so that the maximum height reached by the top of the ball is 45 cm, as shown. 80 60 40 20 If the ...
*Saturday, May 31, 2014 at 12:34am*

**Physics **

A 2.5-kg block is sliding along a rough horizontal surface and collides with a horizontal spring whose spring constant is 320 N/m. Unstretched, the spring is 20.0 cm long. The block causes the spring to compress to a length of 12.5 cm as the block temporarily comes to rest. ...
*Friday, May 30, 2014 at 10:23pm*

**Physics **

Two masses are connected by a string over an ideal pulley as shown. The coefficient of kinetic friction between m1 and the table surface is 𝜇. Find an expression for their common speed after the blocks have moved a distance L. You can assume that you know: m1, m2, L, ...
*Friday, May 30, 2014 at 10:23pm*

**Physics **

A box is pushed down an incline from point A to point B by a force F (and also under the influence of its weight). The distance from A to B, along the ramp, is 5.0 m. The force F is parallel to the incline, as shown, and has a magnitude of 2.0 N. The force of kinetic friction ...
*Friday, May 30, 2014 at 10:22pm*

**Physics **

A projectile is launched at an angle of 34.0o above the horizontal. The projectile has a mass of 1.50 kg and is given an initial speed of 20.0 m/s. a) What is the initial kinetic energy of the projectile? b) By how much does the gravitational potential energy of the projectile...
*Friday, May 30, 2014 at 10:22pm*

**Physics **

A pendulum consists of a swinging mass hanging from a massless string. The hanging mass is 2.0 kg and the string is 400.0 cm long. If the mass has a speed of 8.0 m/s when it passes the lowest point of its swing, a) what is the speed when the string makes an angle of 60.0o with...
*Friday, May 30, 2014 at 10:21pm*

**Physics **

A block of mass 12.0 kg is initially sitting at rest on a 30.0o incline. There is a spring mounted to the ramp with spring constant k = 13500 N/m. The block is released to slide down the incline and comes to a stop momentarily after the spring has been compressed a distance ...
*Friday, May 30, 2014 at 10:21pm*

**Physics**

A 2.50 kg fireworks shell is fired straight up from a mortar and reaches a height of 110. m. (a) Neglecting air resistance (a poor assumption, but we will make it for this example), calculate the shell’s velocity when it leaves the mortar. (b) The mortar itself is a tube ...
*Friday, May 30, 2014 at 7:02pm*

**Physics**

A 75.0 kg skydiver is free falling at 65.0 m/s when she pops her parachute. As the 'chute opens she slows to 5.50 m/s over a distance of 45.0 m. What force does the parachute exert of her harness during this time?
*Friday, May 30, 2014 at 7:01pm*

**physics**

The equation for distance is d = st. How far does a car go in 10 seconds at a speed of 44 m/s?
*Friday, May 30, 2014 at 1:57pm*

**physics**

A body is projected vertically upwards with a speed of 40 m/s.Find the distance travelled by body in last second of upward journey?(g=9.8m/s2 neglect effect of air resistance)
*Friday, May 30, 2014 at 2:37am*

**physics**

an object is dropped from the window of an apartment in a high rise building reaches the ground in 3 seconds. on which floor the apartment is located if height of each floor is 4m and window is 1 meter above the ground of that floor?
*Friday, May 30, 2014 at 1:17am*

**physics**

a wooden slab starting from rest slide down a 10m long inclined plane with acceleration of 5m per sec what would be the speed ay the bottom of the inclined plane
*Friday, May 30, 2014 at 1:03am*

**physics**

A 0.180 kg block on a vertical spring with spring constant of 4.00 ✕ 103 N/m is pushed downward, compressing the spring 0.061 m. When released, the block leaves the spring and travels upward vertically. How high does it rise above the point of release?
*Thursday, May 29, 2014 at 11:51pm*

**physics**

An 66.0 N box of clothes is pulled 5.5 m up a 30.0° ramp by a force of 116 N that points along the ramp. If the coefficient of kinetic friction between the box and the ramp is 0.22, calculate the change in the box's kinetic energy.
*Thursday, May 29, 2014 at 11:49pm*

**physics**

A 56.0 kg diver steps off a diving board and drops straight down into the water. The water provides an upward average net force 1310 N. If the diver comes to rest 4.1 m below the water's surface, what is the total distance between the diving board and the diver's ...
*Thursday, May 29, 2014 at 11:40pm*

**physics**

A rock is dropped from a sea cliff, and the sound of it striking the ocean is heard 3.2 s later. If the speed of sound is 340 m/s, how high is the cliff? vo= 0; s=340 m/s; t= 3.2s h=? t1+t2= 3.2 s t2= 3.2-t1 I used Eq: h= vo*t^1+1/2at^2 rearranged eq. h= (4.9)(t)^2 t^2= h/4.9 ...
*Thursday, May 29, 2014 at 11:31pm*

**Physics**

The pressure at a depth of 300 m in the ocean exceeds sea-level atmospheric pressure by 3.03 kPa. By how much does the volume of a 0.2-m3 aluminum object contract when lowered to this depth in the ocean? The bulk modulus of aluminum is 7 x 10^10 Pa.
*Thursday, May 29, 2014 at 9:39pm*

**physics**

A pair of sleds weighs 25kg and experiences a frictional force of 25N. If a dog team applies a 175N force pulling it 12m. 1. Find the work done by friction 2. Find the work done by the dog team 3. Find the net work done I need to compare my answers so the could you please post...
*Thursday, May 29, 2014 at 9:30pm*

**Physics**

a person pushes on a hockey puck with their stick at an angle so the vertical force is 22N down and the horizontal force is 45N forward. Assume the ice is frictionless. What is the actual force the hockey player transmits to the puck? what is the work done by the person ...
*Thursday, May 29, 2014 at 9:21pm*

**Physics**

A relative of yours belly flops from a height of 2.50 m (ouch!) and stops moving after descending 0.500 m underwater. Her mass is 62.5 kg. What was the magnitude of her acceleration in the pool? Assume that it is constant. How long was she in the water before she stopped ...
*Thursday, May 29, 2014 at 9:10pm*

**Physics! Help **

Calculate the net or resultant force in N in x direction given that F1=96.2 N is applied at angle of α=55.4° and a second F2=11.6 N is applied at angle of β=41.2°. See attached figure. Express your answer to 4 significant figures.
*Thursday, May 29, 2014 at 8:45pm*

**Physics**

Find the magnitude of the impulse delivered to a soccer ball when a player kicks it with a force of 1350N. Assume that the player’s foot is in contact with the ball for 6.20x10-3s.
*Thursday, May 29, 2014 at 8:33pm*

**Physics**

ohn and Jack are planning to do a physics lab related to vectors. Starting at the door of their physics classroom, they walk 2.0 meters, south. They make a right hand turn and walk 16.0 meters, west. They turn right again and walk 24.0 meters, north. They then turn left and ...
*Thursday, May 29, 2014 at 7:20pm*

**Physics**

A seagull can fly with a speed of 12.5 m/s (relative to the air). (a) How long will it take the gull to fly from his perch 420. m east to the carcass of a dead fish floating in the water if the wind is from the east at a speed of 2.70 m/s? (b) Having eaten lunch (nicely aged, ...
*Thursday, May 29, 2014 at 12:36pm*

**physics**

A swing is drawn to the side 3m from its equilibrium position and released. The swing is 2m on the other side of the equilibrium position 1.64s later. Find the angular frequency of the SHM.
*Thursday, May 29, 2014 at 12:27pm*

**physics**

A box has a mass of 0.220 kg. It is on a very smooth (frictionless) horizontal surface and is acted upon by a force of 2.36 N at an angle of θ = 44.8° with the horizontal. The magnitude of the acceleration of the box is m/s2?
*Thursday, May 29, 2014 at 11:54am*

**physics**

The power output of a star is 7.22 x 1028 watts. Every 47.0 seconds, the star converts _________ kg of its mass into energy.
*Wednesday, May 28, 2014 at 10:27pm*

**Physics **

The piolt of an airplane wishes to fly due north, but there is a 65-km/h wind blowing toward the east. in what direction should the pilot head her plane if its speed relative to the air is 340 km/h?
*Wednesday, May 28, 2014 at 8:16pm*

**Physics**

A batter hits a ball and it is caught 4 seconds later 100 meters from home plate. What is the initial velocity of the ball?
*Wednesday, May 28, 2014 at 8:08pm*

**physics **

how much force is required to stop a 100 mi/hr fastball? assume the catcher's mitt stops the ball in 1 millisecond and the mass of a baseball is 145 g
*Wednesday, May 28, 2014 at 8:01pm*

**physics**

Two cars, A and B, travel in the same direction on a straight section of highway. A has a speed of 69.5 km/h, and B a speed of 84.3 km/h (both relative to the earth). (b) If A is initially 394 m in front of B, how long will it take for B to reach A?
*Wednesday, May 28, 2014 at 7:16pm*

**Physics**

Someone in a car going past you at the speed of 24 m/s drops a small rock from a height of 1.6 m. How far from the point of the drop will the rock hit the ground? The acceleration due to gravity is 9.8 m/s2.
*Wednesday, May 28, 2014 at 6:46pm*

**physics**

At a certain undisclosed place (probably not on Earth) an Atwood's like experiment gives the graph of 1/t2 vs Δm the slope is 3.8 (in 1/(kg s2). One also knows that h=1.3m, total mass =0.8kg and I/r2 = 0.08kg. what is the gravitational acceleration is (in m/s2)?
*Wednesday, May 28, 2014 at 5:07pm*

**physics**

For the system on the diagram, the string is massless, and slides over the pulley without friction. The masses are m1 = 5.7kg and m2 = 6.4kg. what is the magnitude of the acceleration of the system is ( in m/s2)
*Wednesday, May 28, 2014 at 5:04pm*

**physics**

I weigh 130 pounds, so how much would I weight on a neutron star?
*Wednesday, May 28, 2014 at 3:16pm*

**physics**

Given the position function s(t) = t cos t, find the velocity function. Answer v(t) = -sin t v(t) = sin t v(t) = cos t - t sin t v(t) = cos t + t sin t
*Wednesday, May 28, 2014 at 2:27pm*

**Physics**

The average person passes out at an acceleration of 7g (that is, seven times the gravitational acceleration on Earth). Suppose a car is designed to accelerate at this rate. How much time would be required for the car to accelerate from rest to 61.8 miles per hour?
*Wednesday, May 28, 2014 at 1:55pm*

**physics**

a flying bat emits squeaks of frequency 80 kHz.if a stationary observer hears the frequency of the squeaks as 78kHz,is the bat moving towards or away from the observer?determine the speed at which the bat is flying.
*Wednesday, May 28, 2014 at 12:53pm*

**Physics**

An 80 kg man is put into a tank of water. When completely submerged he displaces 75 L of water. If fatty body tissue has an average density of 0.9 kg/L and non-fatty body tissue has an average density of 1.1 kg/L, what percentage of the man is composed of fat?
*Wednesday, May 28, 2014 at 2:51am*

**Physics **

A 69.5kg football player is gliding across very smooth ice at 2.15m/s . He throws a 0.470kg football straight forward. A) What is the player's speed afterward if the ball is thrown at 16.0m/s relative to the ground? B) What is the player's speed afterward if the ball ...
*Tuesday, May 27, 2014 at 11:03pm*

**Physics**

A rock is thrown directly upward from the edge of a flat roof of a building that is 56.3 meters tall. The rock misses the building on its way down, and is observed to strike the ground 4.00 seconds after being thrown. Take the acceleration due to gravity to have magnitude and ...
*Tuesday, May 27, 2014 at 9:59pm*

**physics**

The three objects in the drawing are connected by strings that pass over massless and friction-free pulleys. The objects move, and the coefficient of kinetic friction between the middle object and the surface of the table is 0.100. (Assume m1 = 12.2 kg and m2 = 26.0 kg.)
*Tuesday, May 27, 2014 at 9:13pm*

**Physics**

0.2295
*Tuesday, May 27, 2014 at 8:32pm*

**Physics**

A jet engine produces a sound level of 150 dB from a distance of 30 m (assuming spherical dissipation). The average human ear has an effective area of 12.0 cm2. What is the sound level at 60 m from a jet engine is? What would the power intercepted by an unprotected ear at 60 m...
*Tuesday, May 27, 2014 at 8:28pm*

**Physics**

The flux density through a 200 turn coil of area 8.5*10^-4 m squared changes from 0.03 T to 0.12 T in 15 mins. Calculate the induced emf in the coil.
*Tuesday, May 27, 2014 at 8:26pm*

**Physics**

A person’s arm is held with the upper arm vertical, the lower arm and hand horizontal. Find the center of mass of the arm in this configuration, given the following data. upper arm has a mass of 2.5kg and a COM 0.18m above the elbow, lower arm has a mass of 1.6kg and a ...
*Tuesday, May 27, 2014 at 7:55pm*

**Physics**

A 97kg astronaut and a 1100kg satellite are at rest relative to the space shuttle. The astronaut pushes on the satellite, giving it a speed of 0.13m/s directly away from the shuttle. Seven and a half seconds later the astronaut comes into contact with the shuttle. What was the...
*Tuesday, May 27, 2014 at 7:54pm*

**Physics**

A block with mass M = 5.00 kg rests on a frictionless table and is attached by a horizontal spring (k = 130 N/m) to a wall. A second block, of mass m = 1.25 kg rests on top of M. The blocks are displaced by 10 cm then released. If the coefficient of static friction between the...
*Tuesday, May 27, 2014 at 7:08pm*

**Physics**

A 69.5kg football player is gliding across very smooth ice at 2.15m/s . He throws a 0.470kg football straight forward. A) What is the player's speed afterward if the ball is thrown at 16.0m/s relative to the ground? B) What is the player's speed afterward if the ball ...
*Tuesday, May 27, 2014 at 6:40pm*

**physics**

A damp washcloth is hung over the edge of a table to dry. Thus, part (mass = mon) of the washcloth rests on the table and part (mass = moff) does not. The coefficient of static friction between the table and the washcloth is 0.350. Determine the maximum fraction [moff/(mon + ...
*Tuesday, May 27, 2014 at 6:03pm*

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