Monday

October 24, 2016
**Physics**

A car (1100kg) skids up a hill inclined at 6 degrees. Its initial speed is 20m/s and skids 50m before stopping. When it stops, how high is it above where it started? How much potential energy did it gain? How much energy was lost to friction? What is the force of friction (...

*Tuesday, February 23, 2016 by Mary-Lynn*

**Physics**

Water flows over a section of Niagara Falls at the rate of 1.3 × 106 kg/s and falls 49.8 m. How much power is generated by the falling water? The acceleration of gravity if 9.81 m/s^2.

*Tuesday, February 23, 2016 by Spooby*

**Physics**

A student weighing 673 N climbs at constant speed to the top of an 11 m vertical rope in 14 s. What is the average power expended by the student to overcome gravity?

*Tuesday, February 23, 2016 by Spooby*

**physics **

A boxcar of mass 3.21 x 10^4 kg is rolling south at 5.16 m/s when it collides and couples with another boxcar of mass 5.18 x 10^4 kg that is rolling north at 2.38 m/s. What is the velocity of the coupled boxcars after collision? Take north as positive and express your result ...

*Tuesday, February 23, 2016 by lizbeth*

**PHYSICS ASAP PLEASE**

A pellet (20g) is launched horizontally off a cliff (20m high) from a spring-loaded gun. The spring has constan k=1800 N/m and is compressed 0.10m before launch. How much kinetic energy does the pellet have just before it hits the ground? How fast will the pellet be going just...

*Tuesday, February 23, 2016 by Daniel*

**Physics**

An outfielder throws a 2.12 kg baseball at a speed of 114 m/s and an initial angle of 54.8 ◦ . What is the kinetic energy of the ball at the highest point of its motion?

*Tuesday, February 23, 2016 by Spooby*

**Physics**

Melvin pulls a sled across level snow with a force of 345 N along a rope that is 31◦ above the horizontal. If the sled moved a distance of 34.5 m, how much work did Melvin do?

*Tuesday, February 23, 2016 by Spooby*

**Physics**

A bike pump has a 2.3 cm diameter piston that can move a maximum length of 35 cm. How much work is done on the air in the pump if the initial pressure is 1 atm and the final pressure is 4.4 atm?

*Tuesday, February 23, 2016 by Aly*

**Physics**

An artillery gun on a battle ship is capable of launching a shell at a vertical velocity of 400 m/s. A target is 40 Km away and 500 m above the ground. what is the maximum range the target can be away from the gun if the target is 500 m above the ground?

*Tuesday, February 23, 2016 by Abdul*

**Physics**

A pellet (20g) is launched horizontally off a cliff (20m high) from a spring-loaded gun. The spring has constant k= 1800 N/m and is compressed 0.10m before launch. How much energy is stored in the spring before launch? If all that energy is transferred to the pellet, how fast ...

*Tuesday, February 23, 2016 by Danielle*

**Spring Physics**

A block of mass 3 kg is hung from a spring, causing it to stretch 9 cm at equilibrium. The 3 kg block is then replaced by a 4 kg block, and the new block is released from the position shown below, at which point the spring is unstretched.WHAT IS THE LENGTH OF THE SPRING AT ...

*Tuesday, February 23, 2016 by Jennifer*

**physics**

A boxcar of mass 3.21 x 10^4 kg is rolling south at 5.16 m/s when it collides and couples with another boxcar of mass 5.18 x 10^4 kg that is rolling north at 2.38 m/s. What is the velocity of the coupled boxcars after collision? Take north as positive and express your result ...

*Tuesday, February 23, 2016 by lizbeth*

**Physics**

When the body temperature drops, this has the effect of reducing the potential across the axonal membrane slightly. At a body temperature of 30°C, the potential difference experimentally measured concentration of Na+ ions inside the lipid bilayer is 10^18 NA+ ions/cm^3. a...

*Tuesday, February 23, 2016 by Physics lover *

**Physics**

We can physically model the axonal membrane (axolemma) as a parallel plate capacitor with dielectric in it. If the capacitance per unit area in F/m^2 is known, what single additional parameter needs to be measured in order to determine the dielectric constant k of the membrane...

*Tuesday, February 23, 2016 by Physics lover *

**physics**

A two-stage rocket moves in space at a constant velocity of 4800 m/s. The two stages are then separated by a small explosive charge placed between them. Immediately after the explosion the velocity of the 1290-kg upper stage is 5600 m/s in the same direction as before the ...

*Tuesday, February 23, 2016 by Tara*

**physics**

A lumberjack (mass = 98 kg) is standing at rest on one end of a floating log (mass = 235 kg) that is also at rest. The lumberjack runs to the other end of the log, attaining a velocity of +3.2 m/s relative to the shore, and then hops onto an identical floating log that is ...

*Tuesday, February 23, 2016 by Tara*

**Physics**

The figure shows an arrangement in which four disks are suspended by cords. The longer, top cord loops over a frictionless pulley and pulls with a force of magnitude 93.4 N on the wall to which it is attached. The tensions in the shorter cords are T1 = 61.4 N, T2 = 41.5 N, and...

*Tuesday, February 23, 2016 by Nick*

**Physics**

Three uniform spheres are located at the corners of an equilateral triangle. Each side of the triangle has a length of 2.50 m. Two of the spheres have a mass of 4.40 kg each. The third sphere (mass unknown) is released from rest. Considering only the gravitational forces that ...

*Tuesday, February 23, 2016 by K*

**Physics**

A truck is moving away at 30 mph from a car moving towards the truck at 60 mph. If the truck emits a horn of frequency 500 Hz, what frequency does the driver of the car hear to 3 significant digits? how do i solve i know the answer is 519hz but how?

*Tuesday, February 23, 2016 by Victor*

**physics**

A snowball rolls of a roof by accident. The roof is sloped 40.0 o relative to the horizontal. The edge of the roof is 14.0 m above the ground, and the speed of the snowball is 7.00 m/s as it rolls off the roof. Ignore air resistance. Coincidentally, there is a group of ...

*Tuesday, February 23, 2016 by tom*

**physics**

A physics professor moonlights as a daredevil jumping things on a motorbike. His next stunt will be to jump the oldman river on his motorcycle. The ramp is being built 100 m above the river and made an angle of 50.0 o relative to the horizontal. The landing ramp will be 60.0 m...

*Tuesday, February 23, 2016 by tom*

**Physics**

Tennis ball is struck at a speed of 6m/s horizontally. It departs from the racket at a vertical distance of 1.02m. How much time is needed for the ball to hit the ground? Thanks!

*Tuesday, February 23, 2016 by Danniela*

**Physics **

An electron travels at a uniform speed of 2.50 × 106 m/s toward the top of this page. It then enters a uniform magnetic field and experiences a maximum force of 5.15 × 10-8 N that points toward the right of the page. What is the magnitude of the magnetic field? ...

*Tuesday, February 23, 2016 by Erin*

**Physics**

P= 231fraction numerator f t asterisk times l b over denominator s end fraction t= 14.3s W= ?

*Monday, February 22, 2016 by Brooke*

**Physics**

A sphere of mass 85kg is 12m from a second sphere of mass 65kg. A)what is the gravitational force of attraction between them?

*Monday, February 22, 2016 by Sam*

**Physics**

Sally has a mass of 50.0kg and earth has a mass of 5.98X10^24kg. The radius of earth is 6.371x10^6m. A)What is the force of gravitational attraction between sally and earth? B)What is Sally's weight?

*Monday, February 22, 2016 by Sam*

**Physics**

you strike a huge spring at a speed of 30m/s while strapped in a steel cage. When you hit the spring with combined mass of 320kg it is compressed 9.0m. A) What is the spring constant of the spring? B) How long are you in contact with the spring before it bounces off in the ...

*Monday, February 22, 2016 by Sierra*

**Physics**

So you chose to use a solid sphere and you give it a speed of 5.9m/s on a flat horizontal surface which is the speed it has when it reaches a 22degree incline. A) How far along the incline will it go?

*Monday, February 22, 2016 by Sierra*

**physics**

Two railroad freight cars with masses 110 Mg and 150 Mg approach with equal speeds of 0.310 m/s . They collide, the lighter car rebounding opposite its original direction at 0.270 m/s. Find the velocity of the heavier car after the collision. Assume the original direction of ...

*Monday, February 22, 2016 by lizbeth*

**physics**

Can the sun expand

*Monday, February 22, 2016 by TRIX*

**physics**

Drag race tires in contact with an asphalt surface probably have one of the higher coefficients of static friction in the everyday world. Assuming a constant acceleration and no slipping of tires estimate the coefficient of static friction for a drag racer that covers the ...

*Monday, February 22, 2016 by Jade*

**Physics**

At 6400 km above the earth’s surface, an object weighing 71 N on the surface would weigh only 18 N. Acceleration due to gravity will be about ¼ that on the surface of the earth.

*Monday, February 22, 2016 by Joaquin*

**physics**

a conductor is 2m long and 8mm diameter if its resistivity is 1.8*10^-8 ohmm calculate a,the resistance of the conductor b,the current in the conductor when a p.d of 10v is maintained across its ends c,the current density d,the electric field in the wire

*Monday, February 22, 2016 by sol*

**physics**

a rectangular box of mass 400g has a diameter 20cm by 10cm by 5cm compute the pressure it exerts on each face of the box when it rests on a table take g=10m/s2

*Monday, February 22, 2016 by gelila*

**physics **

A man tries to push a crate of 8kg across a rough surface. The static friction coefficient is 0.6 and the kinetic friction coefficient is 0.4. Calculate the friction force exerted on the crate if: a) a horizontal force of 45 N is exerted on the crate and b) a horizontal force ...

*Monday, February 22, 2016 by Stressed out*

**physics**

a wire has a resistance of 6 ohm it is stretched out to a new length which is three times its original length what is the resistance of the longer wire?assume uniform diameter.resistivity and density are constant

*Monday, February 22, 2016 by mat*

**physics**

a 50 kg astronautejects 100 g of gas from his propulsion pistol at a velocity of 50 m/s. what is his resulting velocity?

*Monday, February 22, 2016 by kyla*

**Math/Physics**

I am unsure of what exactly I am looking for in this problem... One of the highlights of the Calaveras Fair, besides the bullfrog jumping contest, is the watermelon seed spitting contest. The seed spitting is being done in the direction of s ⃗=5i ⃗+j ⃗. The ...

*Monday, February 22, 2016 by Wendy*

**Physics 20 **

A 90.3 cm long pendulum is released from a vertical height of 20 cm and is allowed to swing freely. Determine the greatest speed of the pendulum.

*Sunday, February 21, 2016 by Anonymous*

**Physics**

A stone is thrown 60 degrees below the horizontal at 22 ft/sec and 20 meters above the ground. Using the energy equations, determine its velocity when it hits the ground.

*Sunday, February 21, 2016 by Matt*

**physics**

A charge +q is at the origin. A charge -2q is at x = 1.70 m on the +x axis.

*Sunday, February 21, 2016 by Anonymous*

**physics**

A hockey puck is hit on a frozen lake and starts moving with a speed of 14.0 m/s. Five seconds later, its speed is 5.50 m/s. (a) What is its average acceleration? m/s2 (b) What is the average value of the coefficient of kinetic friction between puck and ice? (c) How far does ...

*Sunday, February 21, 2016 by john*

**physics 12U**

A driver parks his car on a hill but accidently leaves it in neutral. The car starts from rest and accelerates down the 45 m long hill. It take the car 12.3 seconds to reach the bottom of the hill. a) What is the final velocity of the car at the bottom of the hill? (ANS: 7.3 m...

*Sunday, February 21, 2016 by emma*

**physics**

A bag of sugar weighs 3.00 lb on Earth. What would it weigh in newtons on the Moon, where the free-fall acceleration is one-sixth that on Earth? N Repeat for Jupiter, where g is 2.64 times that on Earth. N Find the mass of the bag of sugar in kilograms at each of the three ...

*Sunday, February 21, 2016 by mary*

**physics**

A hockey puck is hit on a frozen lake and starts moving with a speed of 14.0 m/s. Five seconds later, its speed is 5.50 m/s. (a) What is its average acceleration? m/s2 (b) What is the average value of the coefficient of kinetic friction between puck and ice? (c) How far does ...

*Sunday, February 21, 2016 by john*

**physics**

A box rests on the back of a truck. The coefficient of static friction between box and bed of the truck is 0.355. (a) When the truck accelerates forward, what force accelerates the box? the inertial force centripetal force the friction force gravity (b) Find the maximum ...

*Sunday, February 21, 2016 by john*

**physics**

A 4.00 kg block is pushed along the ceiling with a constant applied force of 85.0 N that acts at an angle of 55.0° with the horizontal, as in the figure below. The block accelerates to the right at 6.00 m/s2. Determine the coefficient of kinetic friction between block and ...

*Sunday, February 21, 2016 by john*

**physics**

A physics professor moonlights as a daredevil jumping things on a motorbike. His next stunt will be to jump the oldman river on his motorcycle. The ramp is being built 100 m above the river and made an angle of 50.0 o relative to the horizontal. The landing ramp will be 60.0 m...

*Sunday, February 21, 2016 by tom*

**physics**

A snowball rolls of a roof by accident. The roof is sloped 40.0 o relative to the horizontal. The edge of the roof is 14.0 m above the ground, and the speed of the snowball is 7.00 m/s as it rolls off the roof. Ignore air resistance. Coincidentally, there is a group of ...

*Sunday, February 21, 2016 by tamara*

**physics **

A boat is inclined upwards at 30 to the horizontal. the tension of the string is 200N. what is the force tending to raise the boat out of water.

*Sunday, February 21, 2016 by anointed *

**physics**

Three point charges, +6.5 μC, +1.8 μC, and −3.4 μC, lie along the x-axis at 0 cm, 1.7 cm, and 5.4 cm, respectively. What is the force exerted on q1 by the other two charges? (To the right is positive.) The Coulomb constant is 8.99 × 109 N · m2...

*Sunday, February 21, 2016 by anonymous*

**Physics**

You often see birds resting on power lines that carry currents of 48 A. The copper wire on which the bird stands has a radius of 1.5 cm. Assuming that the bird's feet are 3.3 cm apart, calculate the potential difference across its body.

*Sunday, February 21, 2016 by Physics lover *

**Physics**

1. An arrow is shot from the top of a 50 m castle wall at 18 m/s horizontal to the ground. How far from the base of the castle wall will it land? 2. A cannon with a muzzle velocity of 45m/s is shot a various angles to get maximum distance. The general knows that if it is shot ...

*Sunday, February 21, 2016 by Bryan*

**Physics**

what maximizes our ability to recover elastic potential energy?

*Sunday, February 21, 2016 by Mel*

**physics**

A 3.00-kg block starts from rest at the top of a 31.0° incline and slides 2.00 m down the incline in 1.40 s. (a) Find the acceleration of the block. m/s2 (b) Find the coefficient of kinetic friction between the block and the incline. (c) Find the frictional force acting on...

*Sunday, February 21, 2016 by john*

**physics**

A block of mass m = 5.4 kg is pulled up a θ = 24° incline as in the figure with a force of magnitude F = 35 N. (a) Find the acceleration of the block if the incline is frictionless. m/s2 (b) Find the acceleration of the block if the coefficient of kinetic friction ...

*Sunday, February 21, 2016 by john*

**physics**

A 4.00 kg block is pushed along the ceiling with a constant applied force of 85.0 N that acts at an angle of 55.0° with the horizontal, as in the figure below. The block accelerates to the right at 6.00 m/s2. Determine the coefficient of kinetic friction between block and ...

*Sunday, February 21, 2016 by mark*

**physics**

7.–/3 points SerCP9 4.P.063.My Notes Question Part Points Submissions Used A box rests on the back of a truck. The coefficient of static friction between box and bed of the truck is 0.355. (a) When the truck accelerates forward, what force accelerates the box? the ...

*Sunday, February 21, 2016 by mark*

**physics**

A hockey puck is hit on a frozen lake and starts moving with a speed of 14.0 m/s. Five seconds later, its speed is 5.50 m/s. (a) What is its average acceleration? m/s2 (b) What is the average value of the coefficient of kinetic friction between puck and ice? (c) How far does ...

*Sunday, February 21, 2016 by mark*

**physics**

A 5.4-kg bucket of water is raised from a well by a rope. If the upward acceleration of the bucket is 3.7 m/s2, find the force exerted by the rope on the bucket. N

*Sunday, February 21, 2016 by lisa*

**physics**

A 61-kg man standing on a scale in an elevator notes that as the elevator rises, the scale reads 815 N. What is the acceleration of the elevator? m/s2 upward

*Sunday, February 21, 2016 by lisa*

**physics**

A bag of sugar weighs 3.00 lb on Earth. What would it weigh in newtons on the Moon, where the free-fall acceleration is one-sixth that on Earth? N Repeat for Jupiter, where g is 2.64 times that on Earth. N Find the mass of the bag of sugar in kilograms at each of the three ...

*Sunday, February 21, 2016 by lisa*

**physics**

weights of man 10kg and 8kg are placed near p and q respectively one each end of the beam calculate the Reactions at p and q. [1kg is 10N]

*Sunday, February 21, 2016 by joseph*

**physics**

a uniform beam 6.0m long and weighing 4kg on support of p and q placed let and right 1.0m from each end of the beam

*Sunday, February 21, 2016 by joseph*

**Physics**

A particle moves in three dimensional space as an equation r= (t^2+1.34t)i^+(3.34t-2)j^+(2t^3-4t^2)k^ where is in unit of meter and in second. a.Sketch the path of this particle b.Calculate velocity at t=2 s c.Calculate acceleration at t=2 s

*Sunday, February 21, 2016 by Supansa*

**Physics**

(a) Two go-karts, A and B, travel around two circular tracks of radius 5 m and 10 m, respectively, each in 10.34 s. Does A or B have the greater acceleration? Which has the greater speed? (b)If instead the two go-karts travel around the two tracks at the same speed, which has ...

*Sunday, February 21, 2016 by Supansa*

**Physics**

A stone is whirled at the end of a rope 30cm long,makes 10 complete revolution in 2 seconds.find (1)the angular velocity in radians per seconds.(2)the linear speed (3)the distance

*Sunday, February 21, 2016 by Abba*

**Physics**

A 10.0-g marble slides to the left with a velocity of magnitude 0.400 m/s on the frictionless, horizontal surface of an icy New York sidewalk and has a head-on, elastic collision with a larger 30.0-g marble sliding to the right with a velocity of magnitude 0.200 m/s. Let +x be...

*Sunday, February 21, 2016 by Anonymous*

**physics **

1kg of ice at 0C is placed in a container with 2kg of water at 65C. The container is in an atmospheric pressure that remains at 15C. There is a free exchange of energy between all items so that a final temperature of 15C is reached. Calculate the amount of heat transferred to...

*Saturday, February 20, 2016 by Ezekiel *

**physics**

A courier is delivering a 5kg package to an office high in a tall building. (a) What upwards force does the courier apply to the package when carrying it horizontally at a constant velocity of 2m/s into the building? (b) The courier uses the elevator to reach the office. While...

*Saturday, February 20, 2016 by tamara*

**Physics**

A 25 kg box is dragged across a floor by a rope that makes an angle of 60 degrees with the horizontal. The tension in the rope is 100 N while the box is dragged 15 m. A) how much work is done by tension? B) how much work is done by gravity?

*Saturday, February 20, 2016 by Jo*

**physics**

At what height above the ground must a body of mass 10kg besituated in order to have potentral energy possed by another body of mass 10kg maining with velocity of 10ms

*Saturday, February 20, 2016 by lipsy*

**Physics**

(a) Two go-karts, A and B, travel around two circular tracks of radius 5 m and 10 m, respectively, each in 10.34 s. Does A or B have the greater acceleration? Which has the greater speed? (b)If instead the two go-karts travel around the two tracks at the same speed, which has ...

*Saturday, February 20, 2016 by Supansa*

**Physics**

A particle moves in three dimensional space as an equation r= (t^2+1.34t)i^+(3.34t-2)j^+(2t^3-4t^2)k^ where is in unit of meter and in second. a.Sketch the path of this particle b.Calculate velocity at c.Calculate acceleration at

*Saturday, February 20, 2016 by Supansa*

**Physics**

Two students each hit a golf ball at the same speed, but the first student hits his ball at an angle of 60.34o with the horizontal, and the second student hits his at (30-0.34)o with the horizontal. Which ball goes further? Which one hits the ground first? (Neglect air ...

*Saturday, February 20, 2016 by Supansa*

**Physics**

Two heavy balls are released from different heights, one 2.34 s after the other. If the two balls hit the ground at the same time, 4.0 s after the first is released, from what heights were they dropped?

*Saturday, February 20, 2016 by Supansa*

**physics**

A 3250kg truck traveling 44m/s north collides with a 1500kg car traveling 17m/s south. If the two vehicles stick together after the collision, what is the speed and direction of the two vehicles?

*Saturday, February 20, 2016 by Anonymous*

**general physics**

A string going over a massless frictionless pulley connects two blocks of masses 5.9 kg and 9.5 kg. the 5.9 kg block lies on a 31 ◦ incline; the coefficient of kinetic friction between the block and the incline is µ = 0.22. The 9.5 kg block is hanging in the air. ...

*Saturday, February 20, 2016 by David*

**physics**

a baseball is released at rest from the top of a building.it hits the ground after falling for 6seconds . what was the height from which the ball was dropped

*Saturday, February 20, 2016 by winnex*

**Physics**

A point charge is placed at the center of a net uncharged spherical conducting shell of inner radius 2.5 cm and outer radius 4.0 cm. As a result, the outer surface of the shell acquires a surface charge density σ = 71nC/cm2. Find (a) the value of the point charge, and (b...

*Saturday, February 20, 2016 by Kaleem*

**Physics**

How much heat is absorved when a temparature of a piece of iron of mass 0.1kg and specific heat capacity 2*10 rest to power of 2 J/kg/k is rise from 25degree celcius to 75degree celcius

*Saturday, February 20, 2016 by Samuel*

**physics**

what is the work done a bringing a charge from infinity to a point P, if the point P is 5m to the positive y-axis from a charge A(5uC) which is 3m to the left of another charge B(-2uC)?

*Saturday, February 20, 2016 by jay*

**Physics**

A spherical satellite has 12 identical monopropellant thrust chambers for attitude control with the following performance characteristics: thrust (each unit): 5 lbf; Is (steady state or more than 2 sec): 240 sec; Is (pulsing duration 20 msec): 150 sec; Is (pulsing duration 100...

*Friday, February 19, 2016 by Matthew*

**Physics**

some quantity of charge is distributed uniformly over the surface of a thin walled hollow sphere of radius 0.5m. The magnitude of the field is 4.0×10^2N/C at a distance of 6.0m from the center of the sphere. Calculate the quantity of charge on the sphere .

*Friday, February 19, 2016 by Love*

**physics**

A machine with a velocity ratio requires 1000J of work to raise a load of 500N through a vertical distance of 1.7m . find the efficiency and mechanical advantage of the machine.

*Friday, February 19, 2016 by Azeez*

**physics**

A machine with v.r requires 1000J of work to raise a load of 500N through a vertical distance of 1.7m . find the efficiency and m.a of the machine.

*Friday, February 19, 2016 by Azeez*

**physics**

A machine with v.r requires 1000J of work to raise a load of 500N through a vertical distance of 1.7m . find the efficiency and m.a of the machine.

*Friday, February 19, 2016 by Azeez*

**physics 12th**

two halves of a round homogenous cyl inder are held together by a thread wrapped round the cylinder with two weights m are same.the complet cylinder has mass m1=31.4kg find minimum value of m for equlibrium of a cylinder

*Friday, February 19, 2016 by abhijit*

**Physics**

How long it takes a car at 20m/s to come to a stop without friction, obstacles, or breaks ?

*Friday, February 19, 2016 by Nour*

**physics**

why physics is not understandable?

*Friday, February 19, 2016 by namera*

**Physics **

Calculate the thermal energy required to convert 5kg of ice at 0 Celsius to steam at 100 Celsius

*Friday, February 19, 2016 by Lina*

**physics**

A cat dozes on a stationary merry-go-round, at a radius of 4.5 m from the center of the ride. The operator turns on the ride and brings it up to its proper turning rate of one complete rotation every 7.2 s. What is the least coefficient of static friction between the cat and ...

*Thursday, February 18, 2016 by Anonymous*

**Physics**

A synchrotron radiation facility consists of a circular ring that has a 48.0 m radius and creates an electron beam with a current of 497 mA when the electrons have a speed approximately equal to the speed of light. How many electrons pass a given point in the accelerator per ...

*Thursday, February 18, 2016 by Alyssa*

**Physics**

There is current of 115 pA when a certain potential is applied across a certain resistor. When that same potential is applied across a resistor made of the identical material but 30 times longer, the current is 0.044 pA. Compare the effective diameters of the two resistors. d2...

*Thursday, February 18, 2016 by Alyssa*

**Physics**

A 14.1 μF capacitor is charged to a potential of 45.0 V and then discharged through an 80.0 Ω resistor. (a) How long after discharge begins does it take for the capacitor to lose 90.0% of the following? (i) its initial charge in seconds (ii) its initial energy in ...

*Thursday, February 18, 2016 by Alyssa*

**Physics**

Please help me!! I need this as soon as possible. 2.A billiard ball at rest is struck by the cue ball of the same mass whose speed is 5 m/s .After an elastic collision the cue ball goes off at 50 degree with respect to its original direction of motion and the struck ball goes ...

*Thursday, February 18, 2016 by Anonymous*

**Physics**

The near and the far points of a short-sighted are 8 cm and 20 cm from the eyeball. a) What power of corrective lens is needed for this eye to see distant objects clearly? b)What will the resulting near point then be?(Assume that the lens is placed very close to the eye) ...

*Thursday, February 18, 2016 by Sophie*

**physics**

find the approximate current density when an electric field of 5v/m is applied to a copper conductor.the conductivity of copper is 59.6*10^6

*Thursday, February 18, 2016 by mat*

**Physics**

A sign is hanging from three ropes. The tension in the lefthand rope, T1, is 460.80 N. Angle θ1=68.9°, and angle θ2=33.8°.What is the tension, T2, in the righthand rope? What is the mass of the sign?

*Thursday, February 18, 2016 by Rachel*

**Physics**

Block A sits on a horizontal tabletop. There is friction between the surface and Block A. The string passes over a frictionless, massless pulley. Block B hangs down vertically. When the two blocks are released, Block B accelerates downward at a rate of 2.030 m/s2. Block A (...

*Thursday, February 18, 2016 by Rachel*