Sunday

February 14, 2016
**physics**

a disk i = 0.7 kgm and radius 60 cm is rotating a 12 rpm. there is an external torque applied to the outer edge and the rotational speed increases to 35 rpm in 8 sec. angular acceleration? angle the disk rotates? magnitude of applied force (assume tangential)?
*Thursday, January 14, 2016 by kathy*

**Physics**

A 40kg mass hangs from two cables. One cable is at a 25 degree angle. The other cable is horizontally attatched to the mass. Find the tension for each cable
*Thursday, January 14, 2016 by Maria*

**physics**

a string of lenght l and mass m is lying on a horizontal table. a force f is applied at one of its end.tension on the string at a distance y from the end at which the fprce applied is ?
*Thursday, January 14, 2016 by neema*

**physics**

light year is a unit of?
*Thursday, January 14, 2016 by neema*

**physics**

a boy of mass 40 kg hanging from the horizontal branch of a tree .the tension in his arms is minimum when the angle between the arms?
*Thursday, January 14, 2016 by sheethal*

**physics**

Solid A of mass 50 kg resting on a smooth 45º incline is maintained in equilibrium by means of the light string passing over the pulley and holding at its other end a solid B of mass m. Make the inventory of the forces acting on A. Determine graphically the magnitude of ...
*Thursday, January 14, 2016 by angy*

**Physics**

An airplane needs to accelerate at 4.7 m/s2 to reach take-off speed before reaching the end of the runway. The mass of the airplane is 4500 kg. How much force is needed from the engines?
*Thursday, January 14, 2016 by Harry*

**physics**

Find the turn ratio in a transformer which deliver a voltage of 120volts in the secondary coil form a primary voltage at 60v. Please someone should help me with this
*Thursday, January 14, 2016 by khalid idris*

**Physics **

A negatively charged balloon has 4 μC of charge. How many excess electrons are on this bal- loon? The elemental charge is 1.6 × 10−19 C. Answer in units of electrons.
*Thursday, January 14, 2016 by Lily *

**physics**

a sluice gate consists of a quadriant of a circle of radius 1.5m pivoted at its center 0. When the water is level with the gate, calculate the magnitude and direction of the resultant hydrostatic force on the gate and the moment required to open the gate.The width of the gate ...
*Wednesday, January 13, 2016 by shu*

**Physics**

The Earth exerts an 640 N gravitational force on a man. What force does the man exert on the Earth? Answer in units of N.
*Wednesday, January 13, 2016 by Leah*

**PHYSICS**

A ball is thrown upwards .the distance covered by it during of last 2 second before it reaches the maximum height is ???? Find answer
*Wednesday, January 13, 2016 by ABHIJEET *

**Physics II**

Assuming equal point charges, calculate the magnitude of the charge in C if the electrostatic force is great enough to support the weight of a 1.95 mg piece of tape held 1.05 cm above another?
*Wednesday, January 13, 2016 by Sam*

**Physics II**

A test charge of +2 μC is placed halfway between a charge of +6 μC and another of +4 μC separated by 10 cm. What is the magnitude of the force on the test charge?
*Wednesday, January 13, 2016 by Sam*

**Physics**

If a 1350 kg minivan hits a barrier with a force of 2500 n and stops in 2.8 sec, how fast must the minivan have been traveling?
*Wednesday, January 13, 2016 by Kim*

**Physics**

A 0.500 kg object is thrown vertically upward with an average applied force of 8.20 N by a student. The force is applied through a displacement of 1.50m. a. What is the average net force acting on the object? b. What is the velocity of the object when it leaves the student'...
*Wednesday, January 13, 2016 by Jeff*

**Physics**

How many electrons pass a given point in the circuit in 17 minutes? The fundamental charge is 1.602•10^-19. And the current is 0.526315789
*Wednesday, January 13, 2016 by Cynthia H.*

**Physics**

A steel ball of mass 8.0 kg and traveling at 3.0 m/s [E] has a head-on elastic collision with a brass ball which is at rest. After the collision, the velocity of the brass ball is 4.0 m/s [E]. Find: a)the velocity of the steel ball after the collision b) the mass of the brass ...
*Wednesday, January 13, 2016 by paula*

**physics**

Assume the truck is going at v0 = 25 m/s, and you're 20 m behind the truck. You decide to accelerate at a = 1.0 m/s2 to pass the truck. To pass safely, you also want to pass the truck by 20 m before moving back to the lane. Part A ) Estimate the time interval needed to ...
*Wednesday, January 13, 2016 by Sarah*

**PHYSICS**

In your moving car, you covered 2.0 m during the first 1.0 s, 4.0 m during the second 1.0 s, 6.0 m during the third 1.0 s, and so forth. Find the acceleration.
*Wednesday, January 13, 2016 by Katie*

**Physics**

Blood flow rates in the umbilical cord can be found by measuring the Doppler shift of the ultrasound signal reflected by the red blood cells. If the source emits a frequency f, what is the measured reflected frequency fR? Assume that all of the red blood cells move directly ...
*Wednesday, January 13, 2016 by Becky*

**Physics**

A 0.15kg bullet is fired into a 1.85kg block that is hanging from a 45cm string. What minimum initial bullet speed is required if the bullet and block are to make one complete revolution? Please show all work. I need this question answered as soon as possible!
*Wednesday, January 13, 2016 by Sarah*

**Math/Physics**

Lil decides to estimate the height of the Empire State Building. She measures the angle θ of elevation of the spire atop the building as 19°. After walking x = 9.10 ✕ 102 ft closer to the building, she finds the angle to be 23.8°. Use Lil's data to ...
*Wednesday, January 13, 2016 by Courtney*

**Physics**

Two forsec of 5N and 7N act on an object. What are the maximum and minimum of the two forces
*Wednesday, January 13, 2016 by Nana*

**physics**

an object with a mass of 1500g accelerates 10.0 m/s2 when an unknown force is applied to it. What is the amount of the force?
*Wednesday, January 13, 2016 by Jameel Williams*

**Physics**

How many electrons pass a given point in the circuit in 17 minutes? The fundamental charge is 1.602•10^-19. And the current is 0.526315789
*Wednesday, January 13, 2016 by Cynthia H.*

**physics**

A homogeneous rod AB=100 cm of mass m=4kg is suspended from a fixed roof by means of two very light strings OA and O'C having the same length point C is at 20cm from B , rod AB is in a horizontal position of equilibrium Make the inventory of the forces acting on the rod AB.
*Wednesday, January 13, 2016 by sara*

**physics**

A 55.0-kg box rests on a horizontal surface. The coefficient of static friction between the box and the surface is 0.300. What horizontal force must be applied to the box for it to start sliding along the surface?
*Wednesday, January 13, 2016 by chyenne*

**physics**

In the outer space, a constant force is applied to a 32.5 kg probe initially at rest. The probe moves a distance of 100 m in 10 s. (a) What acceleration does this force produce? (b) What is the magnitude of the force?
*Wednesday, January 13, 2016 by chyenne*

**Mathematics, Vector, Physics**

Question: Helicopter is travelling at an air speed of 400kmh-1 with a heading of 70 degrees. a wind is blowing at a speed of 70kmh-1 from the south-east. a.) express the velocity of the helicopter (h) and the wind (w) in component form. b.) express the resultant velocity of ...
*Wednesday, January 13, 2016 by Mat*

**Physics **

An object moves with acceleration given by a = -6t^3 m/s^2. Its initial velocity at t = 0 is 5 m/s. How far will it move before stopping? ((((((The answer is " 7.5 m " ))))) Can you please show me the solution.
*Wednesday, January 13, 2016 by Jane*

**Physics**

How fast must a plane fly at a latitude of 41.9° so that the sun stands still relative to the passengers?
*Wednesday, January 13, 2016 by Tim*

**Physics**

12 kg wagon is being pulled at an angle of 38o above horizontal. What force is applied to the wagon if it accelerates from rest to a speed of 2.2 m/s over a distance of 3.4 m? Is this question a typo? Am I supposed to solve for force or work? Physics - silverback, Tuesday, ...
*Tuesday, January 12, 2016 by silverback - sorry Repost for Damon*

**Physics**

12 kg wagon is being pulled at an angle of 38o above horizontal. What force is applied to the wagon if it accelerates from rest to a speed of 2.2 m/s over a distance of 3.4 m? Is this question a typo? Am I supposed to solve for force or work?
*Tuesday, January 12, 2016 by silverback*

**Physics help **

A 75.0 kg novice skier is going down a hill with several secondary hills. Ignore frictional effects and assume the skier does not push off or slow himself down. If the initial hill is 38.7 m above the chalet level: (8 marks) a) What is the speed of the skier at the bottom of ...
*Tuesday, January 12, 2016 by silverback*

**physics**

A box rests on a frozen pond, which serves as a frictionless horizontal surface. If a fisherman applies a horizontal force with magnitude 48.0 N to the box and produces and acceleration of magnitude 3.00 m/s squ, What is the mass of the box?
*Tuesday, January 12, 2016 by chyenne*

**physics**

A ware house worker pushed a crate along the floor, as shown in fig 4.34, by a force of 10N that points downward at an angle of 45 degrees below the horizontal. Find the horizontal and vertical components of the push.
*Tuesday, January 12, 2016 by chyenne*

**Physics **

A boulder is raised above the ground so that the ground is 200j . Then it is dropped. What is its kinetic energy before it hits the ground?
*Tuesday, January 12, 2016 by Mariah *

**physics**

A ball is thrown up onto a roof, landing 4 sec later at height of 20m above the release level. The balls path just before landing is angled at 60 degree with the roof. a) find the horizontal distance d it travels. b) what is the magnitude of the balls initial velocity? c) what...
*Tuesday, January 12, 2016 by sarah*

**physics**

A block of mass m1=3.70kg on a frictionless plane inclined at angle 30 deg is connected by a cord over a massless, frictionless pulley to a second block mass m2= 2.30kg. What is... a) The magnitude of the acceleration of each block? b) The direction of the acceleration of the ...
*Tuesday, January 12, 2016 by Maryam*

**PHYSICS 1**

The vector signs are above each letter (I just don't know how to show it that way) A= 145 units @ 190 deg. B= 75 units @ 288 deg. C= 210 units @ 85 deg. D= 105 units @ 355 deg. How do I use the component Method with these given magnitude and degree??? Physics Component ...
*Tuesday, January 12, 2016 by ANON*

**PHYSICS**

Is it a must that a nucleus must have opposite nature with the electron
*Tuesday, January 12, 2016 by Stevium*

**PHYSICS**

can an atom exist without a nucleus
*Tuesday, January 12, 2016 by Stevium*

**Physics Component Method**

The vector signs are above each letter (I just don't know how to show it that way) A= 145 units @ 190 deg. B= 75 units @ 288 deg. C= 210 units @ 85 deg. D= 105 units @ 355 deg. How do I use the component Method with these given magnitude and degree???
*Tuesday, January 12, 2016 by ANON*

**physics!**

A point charge of +5 μC is located at the center of a sphere with a radius of 12 cm . What is the electric flux through the surface of this sphere ?
*Tuesday, January 12, 2016 by robinho*

**physics**

Three equal positive point charges q are at the corners of an equilateral triangle with sides of length a. What is the magnitude and direction of the electric field at one corner of the triangle due to two charges placed on another two corners of the triangle ?. These two ...
*Tuesday, January 12, 2016 by THOMAS123*

**physics**

The distance between two charges q1 = -2.5 μC and q2 = 6.0 μC is equal to 1.0 m. Determine the point (other than infinity) at which the electric field is zero.
*Tuesday, January 12, 2016 by THOMAS123*

**Physics**

How much work does a weightlifter do on a 450 N barbell thathe lifts 2m into the air
*Tuesday, January 12, 2016 by Emma Roberts*

**Physics**

a 100 N chandelier hangs from the ceiling on 8 chains. What is the tension force on each chain?
*Tuesday, January 12, 2016 by khushi*

**Physics**

You want to pull a 35 kg steel safe across a pine floor. If the coefficient of static friction between steel and pine is .5, ow hard must you pull to get the safe to move
*Tuesday, January 12, 2016 by Collin*

**physics**

A 31.0 kg child on a swing reaches a maximum height of 1.92 m above their rest position. Assuming no loss of energy: a) At what point during the swing will she attain their maximum speed? b) What will be her maximum speed through the subsequent swing? c) Assuming this maximum ...
*Tuesday, January 12, 2016 by Matt Damon*

**Physics**

A 1 kg apple sits on a table. What is the normal force of the table acting on the apple?
*Tuesday, January 12, 2016 by Leila*

**Physics**

Sarah walks 300 m North ,50 m East and then she walks 300 m South. What is the displacement? Thanks in advance too!!
*Tuesday, January 12, 2016 by Rebecca*

**Physics**

A 31.0 kg child on a swing reaches a maximum height of 1.92 m above their rest position. Assuming no loss of energy: a) At what point during the swing will she attain their maximum speed? b) What will be her maximum speed through the subsequent swing? c) Assuming this maximum ...
*Monday, January 11, 2016 by Matt Damon*

**Physics help **

A 31.0 kg child on a swing reaches a maximum height of 1.92 m above their rest position. Assuming no loss of energy: a) At what point during the swing will she attain their maximum speed? b) What will be her maximum speed through the subsequent swing? c) Assuming this maximum ...
*Monday, January 11, 2016 by Help me in Physics*

**Physics**

A 12 kg wagon is being pulled at an angle of 38degrees above horizontal. What force is applied to the wagon if it accelerates from rest to a speed of 2.2 m/s over a distance of 3.4 m? I not sure how to do this question. Is work involved for this question. I am completely ...
*Monday, January 11, 2016 by I need Physics help*

**physics**

An object in space is initially stationary relative to the Earth. Then, a force begins acting on the object, starting with a force of 0 N, and increasing at a uniform rate until the magnitude of the force is 58 N after the force has acted for 25 s. The body has a mass of 10 kg...
*Monday, January 11, 2016 by jungtaesoo*

**Physics**

A force F = 119 N acts at an angle α = 31◦ with respect to the horizontal on a block of mass m = 22.5 kg, which is at rest on a horizontal plane. The acceleration of gravity is 9.81 m/s 2 . If the static frictional coefficient is µs = 0.72, what is the force ...
*Monday, January 11, 2016 by andrew*

**Physics**

The charge of a proton is 1.6 x 10-19 C. The mass of a proton is 1.673 x 10-27 kg. The constant in the universal law of gravitation is 6.673 x 10-11 Nm2/kg2. The constant in the Coulomb¡¯s law is 9x109 Nm2/C2. Calculate the numerical value of both the gravitational ...
*Monday, January 11, 2016 by Amy*

**Physics **

A 91 kg man stands on a spring scale in an elevator. Starting from rest, the eleva- tor ascends, attaining its maximum speed of 1.7 m/s in 1.07 s. It travels with this constant speed for the next 5 s, undergoes a uniform negative acceleration for 1.67 s, and comes to rest. ...
*Monday, January 11, 2016 by Mariah *

**physics**

You accelerate your 1500 Kg car from 2 m/s to 12 m/s in 2 seconds. How do you determine the cars acceleration initial momentum final momentum change in momentum the force required to do this?
*Monday, January 11, 2016 by Kelley*

**physics**

You accelerate your 1500 Kg from 2 m/s to 12 m/s in 2 seconds. How do you determine the cars acceleration initial momentum final momentum change in momentum the force required to do this?
*Monday, January 11, 2016 by Kelley*

**physics**

Pure helium is closed into cylinder with a movable piston. The initial volume, pressure, and temperature of the gas are 15 dm3, 2·105 Pa, and 300 K, respectively. If volume is decreased to 12 dm3 and the pressure increase to 3.5·105 Pa find the final temperature of ...
*Monday, January 11, 2016 by Thomas*

**physics**

A police car siren emits a sound wave with a frequency fs = 400 Hz and it is moving toward the wall at 25 /m/s. What frequency reflected from the wall does the driver of the police car hear ? The speed of sound is 340 m/s.
*Monday, January 11, 2016 by Thomas*

**Physics**

a 4.50 kg mass traveling east at 5.0 m/s has a head-on elastic collision with a 1.5 kg mass traveling west at 3.0 m/s. find the velocity of each mass after the collision. my work so far: vif= (4.50-1.5/4.50 + 1.5) x2 v2f= (2m1/4.50+1.5) x 2 I don't get the right answer ...
*Monday, January 11, 2016 by Kasey*

**Physics**

If the velocity is given as v=t^2-2t+2 what is the acceleration when v=10m/s?
*Monday, January 11, 2016 by Lisa *

**physics**

Find the potention difference across a resistance whose effective resistance is 10R and its current is 2A
*Monday, January 11, 2016 by jonas*

**Physics**

If the wave is propagated in vacuum and covered a distance of 4.3m along the x-axis in 10seconds. Find it displacement along the y-axis.
*Monday, January 11, 2016 by Ifeoluwa*

**Physics **

How do you do this? A = 145 units @ 190o B = 75 units @ 288o C = 210 units @ 85o D = 105 units @ 355o Find the resultant vector: R = A + B + C + D
*Monday, January 11, 2016 by Jake*

**Physics**

Include units with all of your answers. A 1.84 kg bucket full of water is attached to a 0.76 m long string. a. If you swing the bucket in a vertical circle, what is the minimum speed you must swing it so the water does not fall out at the top of the circle? b. What is the ...
*Monday, January 11, 2016 by Mariah*

**PHYSICS**

Can a massless body undergo repulsion
*Monday, January 11, 2016 by Stevium*

**PHYSICS**

How can a blackhole be stabilized by adding to its angular momentum
*Monday, January 11, 2016 by Stevium*

**Physics**

What mass must be added to 0.9kg trolly to give it an,acceleration of0.4m² when a 0.6n force is applied to it?
*Monday, January 11, 2016 by Lidya*

**Physics**

The brakes of an automobile are suddenly applied at the instant when its velocity is 20 m/s. If the automobile comes to a stop after 5 seconds, what is its acceleration?
*Monday, January 11, 2016 by Harry*

**Physics**

An automobile traveling 50km/hr. It decelerates at 5 meter per second square. How long will it take to stop the car? How far will the car travel after a brakes are applied?
*Monday, January 11, 2016 by Grace*

**Physics**

A stone is projected upward at an angle of 30 degree to the horizontal from the top of a tower 100m and it hits the ground at a point q. If the initial veloity of projection is 100ms cal the maximum height of the stone above the groud
*Sunday, January 10, 2016 by Elvis*

**Physics**

if mars orbits the sun at an angular velocity of 1.06x10-7 rad/s, how long is a year on mars in earth days assuming it travels in a circular orbit?pls explain
*Sunday, January 10, 2016 by Allen*

**Physics**

A 200g ball is dropped from a height of 20m , on impact on a ground, it loses 30j of energy. Calculate the height of a ball as reaches on its rebound. (G=10m/s2
*Sunday, January 10, 2016 by Mewon M Zwuogbae*

**Physics**

The coordinate of a boy running across a parking lot as a function of time is gives as :x0†3=3t*2 7.2t 28 and y0†3=0.28t*2 - 9.1t 30...express the boys position vector r0†3 and velocity v0†3 in unit vector rotation and find the ...
*Saturday, January 9, 2016 by Kay*

**physics**

What would the mass of a bowling ball be if it were to travel m/s with a momentum of 7000kg.m/s
*Saturday, January 9, 2016 by juan*

**physics**

1. A 12 kg wagon is being pulled at an angle of 38o above horizontal. What force is applied to the wagon if it accelerates from rest to a speed of 2.2 m/s over a distance of 3.4 m? (4 marks) 2. A 31.0 kg child on a swing reaches a maximum height of 1.92 m above their rest ...
*Saturday, January 9, 2016 by Anon*

**Physics- just verfiying an equation**

hello, so i'm doing a physics project where I have found the following equation for centripetal force: Fcent=mrù^2 Where f= centripetal force m=mass r=radius ù=angular velocity my question is to make centripetal force greater, does that mean mass, radius and ...
*Saturday, January 9, 2016 by Jesse*

**physics**

A spelunker is surveying a cave. She follows a passage 120 m straight west, then 210 m in a direction 45∘ east of south, and then 280 m at 30∘ east of north. After a fourth unmeasured displacement, she finds herself back where she started. A. Use a scale drawing to...
*Saturday, January 9, 2016 by mohamed*

**physics**

a. A stone is dropped at t = 0 s. A second stone, with a mass 2.0 times that of the first, is dropped from the same point at t = 0.25 s. How far from the release point is the center of mass of the two stones at t = 0.52 s? Assume that neither stone has yet reached the ground. ...
*Saturday, January 9, 2016 by shila*

**physics**

a. A power plant burns coal and generates an average of 610.0 Megawatts (MW) of electrical power while discharging 915.00 MW as waste heat. Find the total electrical energy generated by the plant in a 30-day period. b. Coals vary a lot in their energy content. The energy ...
*Saturday, January 9, 2016 by shila*

**Physics**

A ladder ABC of length 20m is leaning against a wall at an angle from the horizontal. There is a roller at the top of the ladder that rests against the vertical wall. The coefficient of friction between the ladder and the horizontal surface at A is 0.5. Determine: (a) the ...
*Saturday, January 9, 2016 by Lisa *

**physics dimension**

write down the dimensions of moment of inertia and surface tension coefficient.
*Saturday, January 9, 2016 by yaro*

**physics dimension**

in a gas equation (p+a/v^2)(v-b)=RT determine the dimension of the constant a and b;R being the gas constant, v is volume,p is pressure and T is temperature
*Saturday, January 9, 2016 by yaro*

**Physics **

A long thin rod lies along the x-axis from the origin to x=L, with L= 0.750 m. The mass per unit length, λ (in kg/m) varies according to the equation λ = λ0 (1+1.410x3). The value of λ0 is 0.600 kg/m and x is in meters. 1) Calculate the total mass of the ...
*Saturday, January 9, 2016 by David*

**physics dimension **

if the gravitational force F is given by F=GM1M2/r^2 derive the dimension of the constant G.
*Saturday, January 9, 2016 by yaro*

**physics**

The sement bag has a mass of 50 kg an the small pulley has a mass of 2kg ,if the cement bag pulled upwards with an acceleration of 2m/s.fin the force pulling the rope
*Saturday, January 9, 2016 by nurjamal*

**physics**

a particl rotating disc of radius 2m has a constant speed 16m/s.what is size of angular velocity of disc?
*Saturday, January 9, 2016 by Anonymous*

**Physics**

A man can swim at a speed of 3km/hr in still water. He wants to cross a 500m wide river flowing at 2km/hr. He keeps himself always at an angle of 120¡ãwith the water flow while swimming. Find (A) The time he takes to cross the river (B) The point on the opposite ...
*Saturday, January 9, 2016 by Apurv*

**Physics with Calculus**

qsub1:-2.8uC qsub2: 6.6uC qsub2 sits 7.9 cm away from qsub2, and in a previous question moved up the y axis 2.7cm. The question that I am having difficulty with has added qsub3 in the middle of of qsub1 and qsub2, changing the magnitude of Fsub2net= 7.954. What is the sign and...
*Saturday, January 9, 2016 by Jessica*

**Physics**

Charges q1 and q2 lie on the x-axis at points x= -a and x= +a respectively a) how must must q1 and q2 be related for the net force +Q placed at x= +a/2 to be zero?
*Saturday, January 9, 2016 by Ibrahim*

**physics dimention**

the force of capillarity in plant is given by F=yrgh/2,where y is the coefficient of surface tension.Is this equation correct or not? justify your answer.
*Friday, January 8, 2016 by yaro*

**physics dimensions**

the displacement of a particles is given by S=A+Bt+Ct^2.deduce the values of the constant A,B,and C appearing in the equation
*Friday, January 8, 2016 by Anonymous*

**Physics**

The rear window in a car is approximately a rectangle, 1.31 m wide and 0.390 m high. The inside rear-view mirror is 0.440 m from the driver's eyes, and 1.42 m from the rear window. What is the minimum height of the rear-view mirror if the driver is to be able to see the ...
*Friday, January 8, 2016 by Alex*

**Physics**

On Planet X, an astronaut has maximum walking speed of 1.9 m/s. The astronaut's legs are each 1.3 m long. What is the constant of acceleration due to gravity on Planet X?
*Friday, January 8, 2016 by Someone*

**Physics**

1. What is the speed of a 70kg rock after it has fallen freely for 1000m? 2. How far would a 1kg ball have to fall freely to reach a speed of 100km/h?
*Friday, January 8, 2016 by deidra*