Monday

April 27, 2015

April 27, 2015

**Help with physics!**

Hi! I need some help with some physics questions. 1. When two point charges are moved farther apart, what is true about their resulting electric and gravitational forces? a. both forces stay the same b. gravitational force stays the same but electric force increases c. ...
*Thursday, March 19, 2015 at 8:43pm*

**physics**

A model rocket blasts off from the ground, rising straight upward with a constant acceleration that has a magnitude of 88.6 m/s2 for 1.57 seconds, at which point its fuel abruptly runs out. Air resistance has no effect on its flight. What maximum altitude (above the ground) ...
*Thursday, March 19, 2015 at 8:37pm*

**physics**

the positive point charges + q are placed at three corners of a square , and a negative point charge -Q is placed at the fourth , corner. the side of the square is L. calculate the net electric force that positive charges exert on the negative charge
*Thursday, March 19, 2015 at 7:56pm*

**physics**

Unpolarized light from an incandescent lamp has an intensity 112.0 Cd as measured by a light meter. a) What is in Cd the intensity reading on the meter when a single ideal polarizer is inserted between the bulb and the meter? b) What is in Cd the intensity reading on the meter...
*Thursday, March 19, 2015 at 7:46pm*

**physics**

In an historical movie, two knights on horseback start from rest 79.0 m apart and ride directly toward each other to do battle. Sir George's acceleration has a magnitude of 0.319 m/s2, while Sir Alfred's has a magnitude of 0.391 m/s2. Relative to Sir George's ...
*Thursday, March 19, 2015 at 7:22pm*

**Physics**

For the normal force exerted on the book by the wedge in the diagram, which force(s) complete(s) the force pair for Newton’s third law (action-reaction)? 1) the sum of the component of gravity perpendicular to the surface of the incline and the component of Fhand ...
*Thursday, March 19, 2015 at 7:20pm*

**Science, Physics**

Concave mirrors can be used as for shaving or applying make up. The face must be inside the focus. You hold a concave mirror, with a focal length of 40 cm, about 30 cm from your face. Where is your image located? How much bigger than your face is the image?
*Thursday, March 19, 2015 at 6:16pm*

**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 ...
*Thursday, March 19, 2015 at 6:04pm*

**Question**

Are there any physics teachers on this site that can help? I've posted many questions on here but none of them get answered.
*Thursday, March 19, 2015 at 5:53pm*

**physics**

a golfer hits a golf ball an initial velocity of 54m/s [42 degrees above the horizontal]. the ball lands on an elevated green that is 14m higher that the level from which the golfer hit the ball. a) how far away horizontally from the golfer does the ball land? b) what is the ...
*Thursday, March 19, 2015 at 2:59pm*

**physics**

A snowboarder is trying to gap a 14m wide road. He leaves the 19m high cliff at 10m/s at 30 degrees. Questions: 1. Does he make it? 2.When the snowboarder is 16m above the road, what is his speed?
*Thursday, March 19, 2015 at 2:15pm*

**physics**

A golfer is attempting to hit the ball onto an 18m green over a gorge. The location where the ball is hit from is elevated 35m above the green which is 65m away. Assume the ball was hit at a velocity of 20m/s at 40 degrees: Questions: 1. does the ball land on the green and why...
*Thursday, March 19, 2015 at 2:14pm*

**physics**

if an iron cube of volume 400cm3 is immersed in water,the upthrust will be?
*Thursday, March 19, 2015 at 11:28am*

**physics**

calculate the average angular acceleration and initial angular velocity of a wheel that has w=1.5wo(initial omega) at the end of 1min and w=45rev/sec at the end of 3min
*Thursday, March 19, 2015 at 9:12am*

**physics**

. A copper wire 1.00 mm in diameter is used to support a mass of 6.0 kg. If the wire was stretched by 2.00 mm, what was the original length of the wire? Y = stress/ strain r= 0.5 mm =5 X 10-4 m e= 2mm or 2 X 10-3 Given : m = 6 kg F = 60 N A =π r2 = ( 3.14)( 5 X 10-4) (5 X...
*Thursday, March 19, 2015 at 4:23am*

**physics**

A 50 kg girl runs up the stairs to a floor 6m higher in 10 s. What is her power output? P=f.dt P=(50kg x 10m/s2 x6m) __________________ 10 = 300J/s or 300 watts
*Thursday, March 19, 2015 at 4:14am*

**physics**

An electron has an initial velocity of 2.00 ✕ 10 6 m/s in a uniform 6.00 ✕ 10 5 N/C strength electric field. The field accelerates the electron in the direction opposite to its initial velocity. (a) What is the direction of the electric field? (b) How far does ...
*Thursday, March 19, 2015 at 2:27am*

**Physics **

Three collinear charges +7.0 x10^-5 C , +4.8 x10*-5 C, and -8.0 x 10^-5 C exert forces on each other. The first and second charges are 35.0 cm apart. The second and third charges are 35.0 cm apart. What is the magnitude and charge of the total force on the third charge? I know...
*Thursday, March 19, 2015 at 12:13am*

**physics help **

Please explain the answers. Thank You 1. A rifle is fired horizontally over a large flat plane. At the instant the rifle is fired, a student drops a second identical bullet from the same height as the rifle. Which bullet hits the ground first? 2. A monkey is hanging from a ...
*Thursday, March 19, 2015 at 12:06am*

**physics**

a golfer hits a golf ball an initial velocity of 54m/s [42 degrees above the horizontal]. the ball lands on an elevated green that is 14m higher that the level from which the golfer hit the ball. a) how far away horizontally from the golfer does the ball land? b) what is the ...
*Thursday, March 19, 2015 at 12:01am*

**Physics**

A 1,280-kg car pulls a 350-kg trailer. The car exerts a horizontal force of 3,600-N against the ground in order to accelerate. What force does the car exert on the trailer? Assume an effective friction coefficient of 0.15 for the trailer.
*Wednesday, March 18, 2015 at 9:22pm*

**Physics**

A projectile is launched from a compressed spring on an inclined plane. The spring constant of the spring is k= 10 N/m, the mass is 1kg and the plane is inclined 30 degrees to the horizontal. If the spring is compressed 15 cm what will be the velocity of the projectile when it...
*Wednesday, March 18, 2015 at 9:11pm*

**physics**

A 1100-kg car moving on a horizontal surface has speed v = 60km/h when it strikes a horizontal coiled spring and is brought to rest in a distance of 3.1m .What is the spring stiffness constant of the spring?
*Wednesday, March 18, 2015 at 8:45pm*

**physics**

Help: A 2 meter long, uniform bar with a mass of 46 kg is suspended from a pin so it can rotate freely. It is supported by a cable half a meter from the end. Find the tension force in the cable and the magnitude and direction of the reaction force at the wall for the bar to move
*Wednesday, March 18, 2015 at 7:42pm*

**physics**

A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 5.04 m/s. The car is a distance d away. The bear is 17.5 m behind the tourist and running at 7.26 m/s. The tourist reaches the car safely. What is the maximum possible value for d?
*Wednesday, March 18, 2015 at 7:15pm*

**physics**

A student pushes a coin off the edge of a counter with some horizontal velocity. At the instant the coin goes over the edge, a second student drops a second coin from countertop level so it falls vertically to the floor. Which coin hits the floor first? please help
*Wednesday, March 18, 2015 at 3:01pm*

**physics**

A taxi hurries for 1 hour 3 minutes wit a constant speed of 118km/hr and then for another 1 hour 9 minutes with a constant speed of 40km/hr. What is its average speed for the total trip?
*Wednesday, March 18, 2015 at 2:06pm*

**physics**

Suppose you want to negotiate a curve with a radius of 50 meters and a bank angle of 15. If the coefficient of friction between your tires and the pavement is 0.50, what is the maximum speed that you can safely use? (NB: friction acts down the slope).
*Wednesday, March 18, 2015 at 11:02am*

**Physics**

Hi guys, I'm a little stuck on this question I'm doing at the moment. If anyone has spare time, I'd be extremely grateful! A lens with 50-cm focal length produces a real image the same size as the object. a)How far from the lens is the object? b)How far from the ...
*Wednesday, March 18, 2015 at 10:53am*

**Physics**

Hello!I was wondering if anybody had the time to help me with this question. I am not sure what equation to use with three polarizing filters! I thought we use Malus' Law, but doesnt seem to work. Any help would be greatly appreciated!! The question: Unpolarized light ...
*Wednesday, March 18, 2015 at 10:41am*

**physics**

You have an RC circuit and you measure the "zero" voltage to actually be 2.385 [Volts]. The peak voltage is measured to be 8.262 [Volts]. At what voltage value will you look for t4 = time stamp for 15/16 total charge?
*Wednesday, March 18, 2015 at 9:55am*

**Physics**

Two systems are formed from a converging lens and a diverging lens, as shown in parts a and b of the drawing. (The point labeled "Fconverging" is the focal point of the converging lens.) An object is placed inside the focal point of lens 1 at a distance of 7.70 cm to...
*Wednesday, March 18, 2015 at 9:13am*

**Physics**

The near point of a naked eye is 32 cm. When an object is placed at the near point and viewed by the naked eye, it has an angular size of 0.068 rad. A magnifying glass has a focal length of 15 cm, and is held next to the eye. The enlarged image that is seen is located 63 cm ...
*Wednesday, March 18, 2015 at 9:11am*

**Physics**

The owner of a van installs a rear-window lens that has a focal length of -0.320 m. When the owner looks out through the lens at an object located directly behind the van, the object appears to be 0.240 m from the back of the van, and appears to be 0.330 m tall. (a) How far ...
*Wednesday, March 18, 2015 at 9:09am*

**physics**

A block of mass 3kg starts from rest and slides down a surface, which corresponds to a quarter of a circle of 1.6m radius. a) if the curved surface is smooth, calculate the speed of the block at the bottom. b) if the block 's speed at the bottom is 4m/s, what is the energy...
*Wednesday, March 18, 2015 at 7:48am*

**physics**

a =4.0 c point charge and a-4.0 point charge are placed as in figure .what is the potential difference va vb between two points
*Wednesday, March 18, 2015 at 7:06am*

**Physics**

A car, starting from rest, accelerates in the positive x direction. It has a mass of 1.10 x 103 kg and maintains an acceleration of 4.6 m/s^2 for 5 s. Assume that a single horizontal force accelerates the vehicle. Determine the power generated by this force.
*Wednesday, March 18, 2015 at 1:30am*

**Physics**

A 58 kg skier is coasting down a 250 slope. Near the top of the slope, her speed is 3.6 m/s. She accelerates down the slope because of the gravitational force, even though a kinetic frictional force of magnitude 71 N opposes her motion. Ignoring air resistance, determine the ...
*Wednesday, March 18, 2015 at 1:29am*

**Physics**

A 120 kg crate on the flatbed of a truck that is moving with an acceleration of 1.5 m/s^2 along the positive x axis. The crate does not slip with respect to the truck undergoes a displacement whose magnitude is 43 m. What is the total work done on the crate by all of the ...
*Wednesday, March 18, 2015 at 1:27am*

**Physics**

A weight lifter is bench-pressing a barbell whose weight is 710 N. He raises the barbell a distance of 0.65 m above his chest then he lowers it at 0.27 m. Determine the work done on the barbell by the weight lifter during:a.)the lifting phase and b.) the lowering phase.
*Wednesday, March 18, 2015 at 1:26am*

**Physics**

A solid sphere, a hoop, and a solid disk. all with equal masses and radii, roll at the same translational speed along a horizontal surface toward a ramp inclined at a 30 degree angle. Which of the three will make it furthest up the ramp before it stops and begins to roll back ...
*Wednesday, March 18, 2015 at 1:04am*

**Physics**

If the force of repulsion between two socks is .003 and they are 2 cm apart what is the charge on each sock
*Wednesday, March 18, 2015 at 12:01am*

**Physics**

How fast (in rpm) must a centrifuge rotate if a particle 8.55 cm from the axis of rotation is to experience an acceleration of 1000 g's? (use 9.8 m/s^2) You may assume constant angular velocity.
*Tuesday, March 17, 2015 at 9:38pm*

**Physics**

A 5.6 kg ball (I=2/3mr^2) starts on a hill 11.3 m above level surface of the ground. The ball then rolls (without slipping) down the hill. What is the linear speed of the ball when it reaches the bottom of the hill?
*Tuesday, March 17, 2015 at 9:34pm*

**Physics**

An ice skater with an initial moment of inertia of 1.44 kg*m^2 is spinning at a rate of 3 revolutions per second. As she extends her arm outward her moment of inertia increases to 2.52 kg*m^2. What is her new angular velocity (in rad/s)?
*Tuesday, March 17, 2015 at 9:33pm*

**physics**

M1 and M2 are two masses connected as shown. The pulley is light (massless) and frictionless. Find the mass M1, given that M2 (7.0 kg) accelerates downwards at 3.39 m/s2, θ is 30o, and μk is 0.45.
*Tuesday, March 17, 2015 at 7:21pm*

**physics**

A girl on top of a building drops a baseball from rest.at the same moment a boy below throws a golfball upwards towards her with a speed of 20m/s.the golfball is thrown from a point 18m below where the baseball is released.how far will the baseball have dropped when it passes ...
*Tuesday, March 17, 2015 at 5:43pm*

**physics**

A cat moving in a desert walks 15m due north, then 6m due east then south calculate the resultant of the cat.
*Tuesday, March 17, 2015 at 5:31pm*

**physics**

A dockworker loading crates on a ship finds that a 17-kg crate, initially at rest on a horizontal surface, requires a 70-N horizontal force to set it in motion. However, after the crate is in motion, a horizontal force of 53 N is required to keep it moving with a constant ...
*Tuesday, March 17, 2015 at 5:24pm*

**physics**

If the speed of sound in air is 340 m/s, what is. approximately the length of a shortest air column closed at one end that will respond to a tuning fork of frequency 134 Hz? Answer in units of cm.
*Tuesday, March 17, 2015 at 4:51pm*

**physics**

The distance between two consecutive nodes of a standing wave is 22 cm. The hand generating the pulses moves up and down through a complete cycle 3.89 times every 4.68 s. Find the velocity of the wave. Answer in units of m/s
*Tuesday, March 17, 2015 at 4:47pm*

**physics**

An automobile having a mass of 1330 kg is driven into a brick wall in a safety test. The bumper behaves like a spring of constant 4.12 × 106 N/m and compresses 4.99 cm as the car is brought to rest. What was the speed of the car before impact, assuming no energy was lost...
*Tuesday, March 17, 2015 at 4:31pm*

**physics**

A planet has a mass of 6.08 × 1023 kg and a radius of 2.62 × 106 m. (a) What is the acceleration due to gravity on this planet? (b) How much would a 63.6-kg person weigh on this planet?
*Tuesday, March 17, 2015 at 1:51pm*

**Physics **

Hi! I need some help with some physics questions. 1. When two point charges are moved farther apart, what is true about their resulting electric and gravitational forces? a. both forces stay the same b. gravitational force stays the same but electric force increases c. ...
*Tuesday, March 17, 2015 at 1:31pm*

**physics**

Two vectors of magnitudes 10 units and 15 units are acting at a point. The magnitude of their resultant is 20 units. Find the angle between them.
*Tuesday, March 17, 2015 at 8:18am*

**physics**

A bock of mass 3kg starts from rest and slides down a surface , which corresponds to a quarter of a circle of 1.6m radius. a) if the curved surface is smooth , calculate the speed of the of the block at the bottom.
*Tuesday, March 17, 2015 at 7:23am*

**Physics**

A block of mass 13.9 kg slides from rest down a frictionless 40.0° incline and is stopped by a strong spring with a spring constant 32.3 kN/m (note the unit). The block slides 7.80 m from the point of release to the point where it comes to rest against the spring. When the...
*Tuesday, March 17, 2015 at 2:59am*

**physics**

A 4 kg projectile has 1400 J of kinetic energy when it leaves the ground. If it has 120 J of kinetic energy at its highest point, how high did it travel?
*Tuesday, March 17, 2015 at 1:40am*

**Physics**

A M2= 6.40 kg mass is released from rest at height h = 6.60 m . Using the law of conservation of energy, determine the speed of the M1= 2.70 kg mass just as the M2= 6.40 kg mass hits the ground.
*Tuesday, March 17, 2015 at 1:02am*

**physics**

Water waves in a lake travel 5.23 m in 1.52 s. The period of oscillation is 0.84 s. What is the speed of the water waves? Answer in units of m/s. what is the wavelength?
*Tuesday, March 17, 2015 at 12:24am*

**Physics**

A baseball player leads off the game and hits a long home run. The ball leaves the bat at an angle of 30.0o from the horizontal with a velocity of 40.0 m/s. How far will it travel in the air? Working out please
*Tuesday, March 17, 2015 at 12:01am*

**physics**

What is the magnitude and direction of an electric field that exerts a 4.00 ✕ 10 -5 N upward force on a - 1.80 µC charge? N/C
*Monday, March 16, 2015 at 11:11pm*

**physics**

A ball is thrown upward. Its initial vertical component of velosity is 30m/s and its initial horizontal component of velosity is 20m/s. What is the ball's speed 2 s later? Give: Viy = 30m/s Vix = 20m/s T = 2 sec a) V = gt =10m/sec2 x 2 sec= 20 m/sec b) c2 = (20m/s)2 + (20m...
*Monday, March 16, 2015 at 10:43pm*

**physics**

Which of the following statements about electric field lines due to static charges are true? (Select all that apply.) Electric field lines can never cross each other. Static charges can create closed loop electric field lines that do not begin or end on a charge. Wider spacing...
*Monday, March 16, 2015 at 10:30pm*

**Physics**

Problem Solving. Anne throws a ball horizontally from the top of a building that is 50 m high. He hopes the ball will reach the swimming pool that is at the bottom of a building 12 m horizontally from the edge of the building. If the ball is to reach the pool, with what ...
*Monday, March 16, 2015 at 10:29pm*

**PHYSICS **

A simple open U-tube contains mercury. When 11.9 cm of water is poured into the right arm of the tube, how high above its initial level does the mercury rise in the left arm? Take the density of mercury to be 13.6 g/cm3 and the density of water to be 1.00 g/cm3.
*Monday, March 16, 2015 at 9:41pm*

**physics**

n automobile traveling at a speed of 29.3 m/s applies its brakes and comes to a stop in 4.9 s. If the automobile has a mass of 1.2 103 kg, what is the average horizontal force exerted on it during braking? Assume the road is level. magnitude N direction
*Monday, March 16, 2015 at 9:17pm*

**physics**

Two ice skaters hold hands and rotate, making one revolution in 2.4 s. Their masses are 60 kg and 70 kg, and they are separated by 1.5 m. Find the angular momentum of the system about their center of mass.
*Monday, March 16, 2015 at 8:44pm*

**Physics**

A 65 kg sprinter completes a 100 m race in 9.83 s. Calculate the average kinetic energy of the sprinter.
*Monday, March 16, 2015 at 4:54pm*

**physics**

dahnay carried a box (5,4)m.the box had a mass of 5kg.dahnay says that over 300J of work was done on the box . is dahnay correct?explain the answer.
*Monday, March 16, 2015 at 4:19pm*

**physics**

dahnay carried a box (5,4)m.the box had a mass of 5kg.dahnay says that over 300J of work was done on the box . is dahnay correct?explain the answer.
*Monday, March 16, 2015 at 3:50pm*

**physics**

1100 kg car accelerates from rest reaching distance of 139 m in 8.7 sec determine average power in KW your answer to 2 decimal places?
*Monday, March 16, 2015 at 2:46pm*

**physics**

how can we derive the work-energy theorem form Newton's second law of motion?
*Monday, March 16, 2015 at 12:52pm*

**physics**

dahnay carried a box (5,4)m.the box had a mass of 5kg.dahnay says that over 300J of work was done on the box . is dahnay correct?explain the answer.
*Monday, March 16, 2015 at 12:47pm*

**physics**

The body of a 1285 kg car is supported on a frame by four springs. The spring constant of a single spring is 2.80 × 104 N/m. Four people riding in the car have a combined mass of 275 kg. When driven over a pothole in the road, the frame vibrates and for the first few ...
*Monday, March 16, 2015 at 11:05am*

**PHYSICS **

find the heat of fusion of ice M copper calorimeter= 50 g M h20 200 g at 30 C M ice=20.45 at 0 C t2= 20C
*Monday, March 16, 2015 at 9:07am*

**Physics (Tension and Springs)**

An archer must exert a force of 375 newtons on the bowstring so that the string makes a 35 degree angle with the vertical. a)find the tension in the bowstring b)if the applied force is replaced by a stretched spring, and the spring is stretched 30 cm from its unstretched ...
*Monday, March 16, 2015 at 8:19am*

**Physics**

A motor cyclist travelling at 12m/s decelerate at 3m/s(squared)? How far does he travel while coming to rest?
*Monday, March 16, 2015 at 6:48am*

**PHYSICS**

a 50kg boy suspends himself from a point on a rope tied horizontally between two vertical poles. the two segments of the rope are then inclined at angles 30 degrees and 60 degrees respectively to the horizontal. the tensions in the segments of the rope is
*Monday, March 16, 2015 at 6:33am*

**physics**

Calculate the gauge pressure inside a soap bubble 0.0002m in radius using the surface tension for soapy water
*Sunday, March 15, 2015 at 8:28pm*

**physics/chemistry**

Okay so I want to solve for refractive index. I'm given the dielectric constant and the permeability M. From what I understand the refractive index is frequency dependent. I'm just unsure what equation to use. n=(Er)^1/2 does not work because the dielectric constant ...
*Sunday, March 15, 2015 at 7:49pm*

**physics **

At the beginning of a new school term, a student moves a box of books by attaching a rope to the box and pulling with a force of F = 88.9 N at an angle of 56◦ , as shown in the figure. The acceleration of gravity is 9.8 m/s 2 . The box of books has a mass of 17 kg and ...
*Sunday, March 15, 2015 at 5:51pm*

**Physics**

An F-18 with a weight of 22500 lbs lands on a carrier with a speed of 120 mph. If the run-out of the arresting cable is 160 ft, what is the planes acceleration in feet per second squared?
*Sunday, March 15, 2015 at 5:33pm*

**physics/chem**

Okay so I want to solve for refractive index. I'm given the dielectric constant and the permeability M. From what I understand the refractive index is frequency dependent. I'm just unsure what equation to use. n=(Er)^1/2 does not work because the dielectric constant ...
*Sunday, March 15, 2015 at 3:26pm*

**physics electromagnetism**

Two long parallel vertical wires 0.3m apart are. ' placed east-west of one another. The current in the westerly wire is 30A and on the other 20A. The horizontal component of the earths magnetic flux density is 2*10^-5. Find the force per unit length on each wire. (The ...
*Sunday, March 15, 2015 at 2:30pm*

**physics**

A 450 kg car traveling north at 30 m/s collides with a 560 kg car traveling west at 35 m/s. If after the collision they become entangled and move off together, (a) what is magnitude of the final momentum of the cars? (b) What is their final speed of the cars? (c) What is their...
*Sunday, March 15, 2015 at 12:59pm*

**Physics**

Two horizontal forces Upper F1 Baseline and F2 act on a 3.6 kg disk that slides over frictionless ice, on which an xy coordinate system is laid out. Force F1 is in the positive x direction and has a magnitude of 7.1 N. Force F2 has a magnitude of 9.3 N. The figure here gives ...
*Sunday, March 15, 2015 at 10:06am*

**physics**

The system is frictionless and the trolley accelerates to the left at 3m/s squared. (a) calculate the unknown mass M. (b) calculate the magnitude of the forces in each string.
*Sunday, March 15, 2015 at 10:01am*

**physics 10**

1.) 100 kJ of heat is added to 600g of zinc at 20 C and 75g of it melts. If the specific heat of zinc is 0.385 kJ/kg-C and it melts at 420 C. What is its heat of fusion? 2.) If all the heat lost by 1kg of water at 0 C when it turns into ice at 0 C could be burn into KE, What ...
*Sunday, March 15, 2015 at 4:32am*

**PHYSICS**

The gravitational forces of the Earth and the Moon are attractive, so there must be a point on a line joining their centers where the gravitational forces on an object cancel. How far is this distance from the Earth's center?
*Sunday, March 15, 2015 at 2:59am*

**physics**

A 55 grams copper calorimeter contains an unknown mass of water at 18 degrees celcius. When 755 grams of alloy at 100 degrees celcius is dropped into the calorimeter ,the resulting temperature is 20.4 degrees celcius. Determine the mass of water.
*Sunday, March 15, 2015 at 12:11am*

**Physics**

You have a solution that contains Ca2+ ions and another that contains Na+ ions. How would adding a solution that contains CO2-3 ions enable you to tell which is which?
*Sunday, March 15, 2015 at 12:09am*

**physics**

when 200 grams of aluminum at 100 degrees celsius is dropped into an aluminum calorimeter of mass 120 grams and containing 150 grams of kerosene at 15 degrees celsius,the mixtures reaches a temperature of 50 degrees celsius.what is the specific heat of kerosene?
*Saturday, March 14, 2015 at 11:33pm*

**Physics**

Assuming atmospheric pressure to be 1.01 x 10^5 Pa and the density of sea water to be 1025 kg/m^3, what is the absolute pressure at a depth of 15.0m below the surface of the ocean? Could you show me how to do this problem? Thank you.
*Saturday, March 14, 2015 at 9:36pm*

**Physics **

1. What is the kinetic energy of a 0.50 g insect traveling in a straight line at 5.0m/s? a. 6.25j b. 1.25j c. 5.0j d. 250j Is the answer A?? 2. Mechanical energy is defined as the sum of which of the following? a. kinetic, potential and radiant energy b. kinetic, potential and...
*Saturday, March 14, 2015 at 9:28pm*

**Physics**

A 1.42 kg ball is connected by means of two massless strings, each of length L = 1.29 m, to a vertical, rotating rod. The strings are tied to the rod with separation d = 1.29 m and are taut. The tension in the upper string is 48.0 N. What are (a) the tension in the lower ...
*Saturday, March 14, 2015 at 4:52pm*

**physics**

A 130-kg crate is initially at rest on a horizontal frictionless surface. An applied force of 400 N to the right is exerted on the crate, causing it to move and cover a distance of 26.0 m. At the end of its path, the crate is found to be moving at a speed of 15.0 m/s. (a) What...
*Saturday, March 14, 2015 at 9:18am*

**Physics**

Hi, can anybody provide some hints in how to approach these questions? I've been stuck on it for days!!! Thank you in advance!! Nodes of a Standing Wave: Consider a standing wave, where y represents the transverse displacement of a string that extends along the x direction...
*Saturday, March 14, 2015 at 5:59am*

**physics**

The density of copper is 8930 kg per cubic metre. A rod of copper is 20 cm long. What length of it will remain immersed in mercury of density 13600 kg per cubic metre
*Saturday, March 14, 2015 at 5:44am*

**physics**

A chair of mass 14.0kg is sitting on the horizontal floor; the floor is not frictionless. You push on the chair with a force F = 40.0N that is directed at an angle of 43.0∘ below the horizontal and the chair slides along the floor.
*Saturday, March 14, 2015 at 5:01am*