Tuesday

July 28, 2015

July 28, 2015

**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 by plzzzzz help*

**physics**

how can we derive the work-energy theorem form Newton's second law of motion?
*Monday, March 16, 2015 by sarah*

**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 by Christina*

**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 by d*

**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 by lollipop225*

**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 by Emily*

**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 by Shweta Chand*

**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 by ESSIEN UBONG*

**physics**

Calculate the gauge pressure inside a soap bubble 0.0002m in radius using the surface tension for soapy water
*Sunday, March 15, 2015 by Boyd*

**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 by Zed*

**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 by Liz*

**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 by Jim*

**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 by Zed*

**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 by pascal*

**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 by John*

**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 by patrick*

**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 by kulani*

**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 by ella *

**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 by Physics*

**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 by john ralph*

**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 by Channing*

**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 by john ralph*

**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 by N.*

**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 by N.*

**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 by Brian*

**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 by jjjj*

**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 by Tommy*

**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 by Suraj *

**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 by Kevin*

**physics**

a car is moving at speed of 50km/hr ,can be stopped by brake at least at 6 m.If the same car is moving at speed of 100 km/hr ,what is the minimum stopping distance?
*Saturday, March 14, 2015 by priya *

**Physics - Mechanics**

A small block of mass 1.2 kg is launched by a compressed spring with force constant k=600 N/m. The initial compression of the spring is 0.15 m. The block slides along a horizontal frictionless surface and then up an inclined plane that makes an angle θ=40˚ with the ...
*Saturday, March 14, 2015 by Anonymous*

**Physics - Mechanics**

A large box of mass M is at rest on a horizontal table whose surface is rough; the coefficient of static friction between the table and the block is μ. The box is connected by a taut string to a small block of unknown mass m, initially held horizontally as shown and then ...
*Saturday, March 14, 2015 by Anonymous*

**Physics - Mechanics**

A bullet of mass m is shot at speed v toward a pendulum bob of mass M. The bullet penetrates through the block and emerges on the other side traveling at speed v/2. 1. What is the speed v_block of the block immediately after the bullet emerges from the block (In terms of M, m ...
*Saturday, March 14, 2015 by Anonymous*

**Physics**

two cars start from rest and begin accerlating, one at 10m/s^2 and the other at 12m/s^2. how long will it take for the second car to be 100m ahead of the first car
*Friday, March 13, 2015 by Yes*

**Physics**

A beam of light makes an angle of θi = 53.0˚ with the normal of a slab of transparent material of t=3.80 mm-thickness. The index of refraction of the glass is n2 = 1.39. Angle 3 is 53.1 b) How far vertically (d) is the point at which the beam leaves the glass surface...
*Friday, March 13, 2015 by Emily*

**physics(Please respond)**

if a rock is dropped into a well and it takes 17 seconds to hit the water how far down is the water level from the top of the well
*Friday, March 13, 2015 by mike*

**college physics**

When a thin 12.0cm iron rod moves with a constant velocity of 6.50m/s perpendicular to the rod, the induced emf across its ends is measured to be 0.300V. What is the magnitude of the magnetic field?
*Friday, March 13, 2015 by a*

**Physics**

In the drawing, the weight of the block on th e table is 380 N and that of the hanging block is 175 N. Ignore all frictional effects, and assuming the pulley to be massless. What is the acceleration of the two block?
*Friday, March 13, 2015 by Cameron*

**physics**

If you do 500J of work to elevate a bucket of water, what is its gravitational potential energy relative to its starting position? 500*10=5,000 5,000/500=10
*Friday, March 13, 2015 by Lara*

**PHYSICS**

A submarine is trapped at the bottom of the ocean with its hatch at a depth of 20 m below the surface. The hatch is circular and 0.40 m. Calculate the force that would have to be exerted against it to open it. The air inside the submarine has a pressure of 1 Atm. -I used P=f/a...
*Friday, March 13, 2015 by Javeria*

**Physics - Mechanics**

A small block of mass 1.2 kg is launched by a compressed spring with force constant k=600 N/m. The initial compression of the spring is 0.15 m. The block slides along a horizontal frictionless surface and then up an inclined plane that makes an angle θ=40˚ with the ...
*Friday, March 13, 2015 by Anonymous*

**Physics - Mechanics**

A large box of mass M is at rest on a horizontal table whose surface is rough; the coefficient of static friction between the table and the block is μ. The box is connected by a taut string to a small block of unknown mass m, initially held horizontally as shown and then ...
*Friday, March 13, 2015 by Anonymous*

**Physics - Mechanics**

A bullet of mass m is shot at speed v toward a pendulum bob of mass M. The bullet penetrates through the block and emerges on the other side traveling at speed v/2. 1. What is the speed v_block of the block immediately after the bullet emerges from the block (In terms of M, m ...
*Friday, March 13, 2015 by Anonymous*

**Physics**

A hollow spherical shell with mass 2.45kg rolls without slipping down a slope that makes an angle of 30.0∘ with the horizontal. a.) find the magnitude of the acceleration of the center of mass of the spherical shell. b.) find the magnitude of the frictional force acting ...
*Friday, March 13, 2015 by Rosae*

**Physics**

A mass of 5Kg is 1st weighed on a balance at the top of a tower 20m high.The man is then suspended from a fine wire 20m long and reweivhed.find the difference in a weight ,assuming that the radius of the earth is 6400km,the mass of the earth is 6×10^24kg and G=6.673&...
*Friday, March 13, 2015 by Olushola*

**physics**

A projectile of mass 0.803 kg is shot straight up with an initial speed of 24.8 m/s. (a) How high would it go if there were no air resistance? (b) If the projectile rises to a maximum height of only 9.36 m, determine the magnitude of the average force due to air resistance
*Thursday, March 12, 2015 by blake*

**Physics**

A hollow spherical shell with mass 2.45kg rolls without slipping down a slope that makes an angle of 30.0∘ with the horizontal. a.) find the magnitude of the acceleration of the center of mass of the spherical shell. b.) find the magnitude of the frictional force acting ...
*Thursday, March 12, 2015 by Rosae*

**Physics**

what is the mass of the toy truck if the force of friction holding it in place is 18.5N u= 0.2 at 30 degrees
*Thursday, March 12, 2015 by mouzam *

**Physics**

A hollow spherical shell with mass 2.45kg rolls without slipping down a slope that makes an angle of 30.0∘ with the horizontal. a.) find the magnitude of the acceleration of the center of mass of the spherical shell. b.) find the magnitude of the frictional force acting ...
*Thursday, March 12, 2015 by Rosae*

**Physics**

A 2.0 lb block is given an initial speed of 4.0 ft/sec up an inclined plane starting from a point 2.0 feet from the bottom as measured along the plane. If the plane makes an angle (theta = 30 degrees) with the horizontal and the coefficient of friction is 0.20, how far up the ...
*Thursday, March 12, 2015 by Nora*

**Physics**

A small wooden block with mass 0.800kg is suspended from the lower end of a light cord that is 1.52m long. The block is initially at rest. A bullet with mass 0.0126kg is fired at the block with a horizontal velocity v0. The bullet strikes the block and becomes embedded in it. ...
*Thursday, March 12, 2015 by Katie*

**Physics**

At New York City, the earth's magnetic field has a vertical component of that points downward (perpendicular to the ground) and a horizontal component of that points toward geographic north (parallel to the ground). What are the magnitude and direction of the magnetic ...
*Thursday, March 12, 2015 by Aggie*

**Physics**

A 100 lb block of ice slides down an incline 5.0 ft long and 3.0 ft high. A worker pushes up on the ice parallel to the incline so that it slides down at constant speed. The coefficient of friction between the ice and the incline is 0.10. Find (a) the force exerted by the ...
*Thursday, March 12, 2015 by Emily*

**Physics**

What kind (s) of particles make up (a) gaseous compounds, (b) liquid compounds, and (c) solid compounds?
*Thursday, March 12, 2015 by Channing*

**physics**

How do I: a.) find the energy in a 3.50x10^-5f parallel plate capacitor if it holds 2.00x10^-3c of charge b.)find the voltage between the plates c.)determine the new voltage after doubling the stored energy
*Thursday, March 12, 2015 by Anonymous*

**physics **

The heaviest invertebrate is the giant squid, which is estimated to have a weight of about 0.35 tons spread out over its length of 38 feet. What is its weight in newtons?
*Thursday, March 12, 2015 by Anonymous*

**Physics**

Assume you have a rocket that requires a change in velocity of DeltaV=9.6km/s . There are two options for the propulsion system --- 1. chemical and 2. electric --- each with a different specific impulse. Using the setting of g0 =9.81m/s^2 to calculate the propellant fraction ...
*Thursday, March 12, 2015 by Janet *

**Physics **

Assume you have a rocket that requires a change in velocity of ¦¤V¡Ö9.6km/s . There are two options for the propulsion system --- 1. chemical and 2. electric --- each with a different specific impulse. Using the setting of g 0 =9.81m/s^2 to calculate ...
*Thursday, March 12, 2015 by Janet *

**Physics**

What is the centripetal acceleration in meters per second squared of a point on the rim of a circle with a radius of 0.45 meters and turning at a rate of 1200 rpm?
*Thursday, March 12, 2015 by George*

**Physics**

A diver running 1.8 m/s dives out horizontally from the edge of the cliff and 3 s later he reaches the water below. (a) Calculate the resultant velocity (with direction) of the diver just before he hits the water. (10) (b) How high is the cliff, and how far from its base did ...
*Thursday, March 12, 2015 by Tina*

**Physics**

A body of mass m is suspended from a spring with spring constant k and the spring is stretched 0.1. If two identical bodies of mass m/2 are suspended from a spring with the same spring constant k, how much will the spring stretch? Explain your answer. The first case is when ...
*Thursday, March 12, 2015 by Justin*

**Physics**

There is a band who uses 10000 W to radiate sound energy in all directions. What was the intensity of sound 10 meters from this speaker? What was the sound level in dB at a distance of 10 m? At what distance from the speaker was the sound level 100 dB?
*Thursday, March 12, 2015 by Josh*

**Physics**

The distance between two consecutive nodes of a standing wave is 19.2 cm. The hand generating the pulses moves up and down through a complete cycle 2.59 times every 7.44 s. Find the velocity of the wave. Answer in units of m/s.
*Wednesday, March 11, 2015 by Lauren*

**Physics**

What is the volume of water at 95 degrees Celcius if at 5 degrees Celcius the water is 5.56L?
*Wednesday, March 11, 2015 by Scott*

**Physics**

A 100 lb block of ice slides down an incline 5.0 ft long and 3.0 ft high. A worker pushes up on the ice parallel to the incline so that it slides down at constant speed. The coefficient of friction between the ice and the incline is 0.10. Find (a) the force exerted by the ...
*Wednesday, March 11, 2015 by Emily*

**Physics**

A raft measures 1.7m x 0.67m x 0.14m, and it has a mass of 13.5kg. What is the maximum mass that the raft can hold and still stay afloat
*Wednesday, March 11, 2015 by Scott*

**physics**

a train stopping distance, even when full emergency brakes are engaged, is 1.3 km. if the train was travelling at an initial velocity of 90 km/h [forward], determine its acceleration under full emergency brakes.
*Wednesday, March 11, 2015 by raman*

**physics**

A light beam in air enters a block of transparent material at an angle of 28.0˚ with respect to the normal. After refraction it makes an angle of 19.0˚ with respect to the normal. a) Find the index of refraction of the material. b) In a second setting, the light ...
*Wednesday, March 11, 2015 by Amanda*

**physics**

A 2.40 kg mess kit sliding on a frictionless surface explodes into two 1.20 kg parts: 3.78 m/s, due north, and 5.28 m/s, 32.8° north of east. What is the original speed of the mess kit?
*Wednesday, March 11, 2015 by Shane*

**Physics**

A 75kg firefighter slides down a 2.5m fire pole from rest. It takes the firefighter 1.8s to reach the ground. If the firefighter bends his knees when he reaches the ground such that his centre of mass mives 41cm while coming to a stop, what must the normal force of the ground ...
*Wednesday, March 11, 2015 by Anonymous*

**Ap physics**

Rotational Motion/Torque The question says that "A 60.0kg painter is on a uniform 25 kg scaffold supported from above by ropes. There is a 5.0 kg pail of paint to one side, as shown. How far from the left end of the scaffold should the painter stand such that the right ...
*Wednesday, March 11, 2015 by Kayla*

**Physics**

A pilot wants to fly directly north to an airport 500 km away. His speed relative to the air is 100 km/h. Howevere there is a 40 km/h cross wind blowing from west to east. At what angle relative to the south north direction should he fly to arrive at the distant airport? How ...
*Wednesday, March 11, 2015 by Alex*

**Physics**

A 75kg firefighter slides down a 2.5m fire pole from rest. It takes the firefighter 1.8s to reach the ground. If the firefighter bends his knees when he reaches the ground such that his centre of mass mives 41cm while coming to a stop, what must the normal force of the ground ...
*Wednesday, March 11, 2015 by Anonymous*

**Physics**

A 75kg firefighter slides down a 2.5m fire pole from rest. It takes the firefighter 1.8s to reach the ground. If the firefighter bends his knees when he reaches the ground such that his centre of mass mives 41cm while coming to a stop, what must the normal force of the ground ...
*Wednesday, March 11, 2015 by Anonymous*

**Physics**

A 100 lb block of ice slides down an incline 5.0 ft long and 3.0 ft high. A worker pushes up on the ice parallel to the incline so that it slides down at constant speed. The coefficient of friction between the ice and the incline is 0.10. Find (a) the force exerted by the ...
*Wednesday, March 11, 2015 by Emily*

**physics**

The angular position of a flywheel is given by theta=(2+5t+2t^2)rad . find the angular speed and acceleration at 3^rd second after the motion had been started.
*Wednesday, March 11, 2015 by help*

**physics**

2) Two objects are initially the same height above the ground. Simultaneously, one is released from rest and the other is shot horizontally with an initial speed of 2.5 m/s. The two objects collide after falling 20.0 m. How far apart were the objects initially?
*Wednesday, March 11, 2015 by Anonymous*

**physics**

2)Two objects are initially the same height above the ground. Simultaneously, one is released from rest and the other is shot horizontally with an initial speed of 2.5 m/s. The two objects collide after falling 20.0 m. How far apart were the objects initially?
*Wednesday, March 11, 2015 by Anonymous*

**physics**

two blocks of each mass m=3.75kg are fastened to the ceiling of an elevator. If the elevator accelerates upward at 1.6m/s^2. Find the tension in T1 and T2 in each upper and lower rope
*Wednesday, March 11, 2015 by Rebecca*

**Physics**

A mover pushes a 60 lb box 30 ft along a level floor at constant speed with a force directed 45 degrees below the horizontal. If the coefficient of kinetic friction is 0.20, how much work does the mover do on the box? ...Is this one of those trick questions where the work is 0?
*Wednesday, March 11, 2015 by Emma*

**physics**

a force of 10N acts on an object and raises its speed from 0 to 5 m/s in 10s.calcuate the average power.
*Wednesday, March 11, 2015 by doc*

**Physics**

A 100 lb block of ice slides down an incline 5.0 ft long and 3.0 ft high. A worker pushes up on the ice parallel to the incline so that it slides down at constant speed. The coefficient of friction between the ice and incline is 0.10. Find the force exerted by the worker. (I&#...
*Wednesday, March 11, 2015 by N*

**Physics**

You count 9 cycles across 8.1 time divisions on an oscilloscope screen. The time sweep is set to 60 micro seconds. The voltage peak is measured to be 22 volts. What is the frequency? You plot some data of Real Frequency versus HP Dial Frequency and get a linear trend of y = 1....
*Wednesday, March 11, 2015 by Isa*

**Physics **

1. Given t1/2 to be 0.0137 seconds, how long should it take to reach 87.5% of maximum charge?
*Tuesday, March 10, 2015 by B*

**Physics**

The coefficient of static friction between the m = 3.75-kg crate and the 35.0° incline of the figure below is 0.320. What minimum force vector F must be applied to the crate perpendicular to the incline to prevent the crate from sliding down the incline?
*Tuesday, March 10, 2015 by Ryan*

**Physics help please!**

1. Given t1/2 to be 0.0137 seconds, how long should it take to reach 87.5% of maximum charge? 2. Let's say you measure t1/2 to be 0.0137 seconds and the resistance in the circuit is 99 Ohms. Then what is the capacitance in micro Farads? 3.q = qmax(1 - e -t / τ) Using ...
*Tuesday, March 10, 2015 by B*

**physics**

*please walk me through equation The patellar tendon attaches to the tibia at the tibial tuberosity. The tibial tuberosity is 7 cm from the center of the knee joint. The patellar tendon pulls at an angle of 35deg to the line passing through the tibial tuberosity and the center...
*Tuesday, March 10, 2015 by eagle1*

**Physics**

Zak, helping his mother rearrange the furniture in their living room, moves a 58.3 kg sofa 7.7 m with a constant force of 25 N. What is the work done by Zak on the sofa? Neglect friction. Answer in units of J. What is the average acceleration of the sofa? Answer in units of m/...
*Tuesday, March 10, 2015 by monica :)*

**Physics**

We want to find how much charge is on the electrons in a nickel coin. Follow this method. A nickel coin has a mass of about 5.7 g. a. Find the number of atoms in a nickel coin. Each mole (6.02 × 10^23 atoms) has a mass of about 57.9 g. Answer in units of atoms. b. Find ...
*Tuesday, March 10, 2015 by Jess*

**Physics**

A charge q1 = 5 µC is at the origin, and a charge q2 = 4 µC is on the x axis at x = 6 m. Find the force on charge q2 . The Colulomb constant is 8.98755 × 10^9 N·m^2/C^2. Answer in units of N.
*Tuesday, March 10, 2015 by Jess*

**Physics**

A strong lightning bolt transfers about 21.45 C to Earth. How many electrons are transferred? The elemental charge is 1.602 × 10^−19 C.
*Tuesday, March 10, 2015 by Jess*

**physics**

A plastic rod is rubbed against a wool shirt, thereby acquiring a charge of −4.9 µC. How many electrons are transferred from the wool shirt to the plastic rod? The elemental charge is 1.6 × 10−19 C.
*Tuesday, March 10, 2015 by Bob*

**physics**

You can estimate your distance from a lightning storm by watching for a lightning flash and then counting in one-second intervals using the general rule that you are 1 km away for every 3 s you count. Explain why this rule works. Estimate the distance from a lightning storm if...
*Tuesday, March 10, 2015 by gal*

**Physics**

If a mass of gasoline occupies 70.01 at 20°C, What is the volume at 35°C?
*Tuesday, March 10, 2015 by Kram *

**Physics**

An object floats in a liquid of density 1.2×10 kg/m3 with one quarter of its volume above the liquid surface. You are required to determine the density of the object
*Tuesday, March 10, 2015 by Kram *

**physics **

A system of 1216 particles, each of which is either an electron or a proton, has a net charge of -5.920×10-17 C. A)How many electrons are in this system (exactly)? B)What is the mass of this system (to three significant digits)?
*Tuesday, March 10, 2015 by Samantha*

**Physics**

Billy stands on a hill without slipping. In which direction is the force of friction acting?
*Tuesday, March 10, 2015 by Hanna*

**Physics College**

A heat engine operates in a Carnot cycle between 78.0°C and 340°C. It absorbs 22,000 J of energy per cycle from the hot reservoir. The duration of each cycle is 3.00 s. (a) What is the mechanical power output of this engine? (answer in kW) (b) How much energy does it ...
*Tuesday, March 10, 2015 by Meena*

**physics**

calculate the linear speed of a point on the record at the beginning and the end of the record that rotates at 33rev/min r1=7cm,r2=15cm
*Tuesday, March 10, 2015 by selena*

**physics**

A car's wheel of radius r=50cm goes through 5000rev in 1min. find the car's average angular velocity,and how far it travels along the ground in 1min. The linear speed v and angular speed w of the point of a rotating body are connected by the equation v=wr. where r is ...
*Tuesday, March 10, 2015 by Sarah*