Saturday

April 30, 2016
**physics**

Freshwater (𝜌 = 1,020 kg/m3) is flowing in a horizontal pipe whose cross section widens from 9.0 cm2 to 13.0 cm2. The water speed at the wide section of the pipe is 1.25 m/s. What pressure difference (absolute value) is there between narrow and wide section?
*Saturday, March 26, 2016 by Morgan*

**physics**

A 1,500-kg car stands on a square platform, and a 25-kg boy stands on another square platform. These platforms are the two caps of a large oil-filled container. What must be the ratio of the platform sides (large/small) for the boy to gently lift the car?
*Saturday, March 26, 2016 by Dylan*

**physics**

A force of 80N acts on a body initially at rest and moves 72m in 6s. If the force is removed after 6s calculate how far the body moves after 6s
*Saturday, March 26, 2016 by jay*

**physics**

explain the physics concept to why a ship sounds when moving in water?
*Saturday, March 26, 2016 by lucy*

**physics**

explain the physics principle why the size of tree stem decreases upwards?
*Saturday, March 26, 2016 by lucy*

**physics**

state or law which explains why a ship can easily sink than overturn?
*Saturday, March 26, 2016 by lucy*

**physics**

why is it cold in winter and hot in summer basing on physics knowledge
*Saturday, March 26, 2016 by lucy*

**Physics**

A man is 2m50cm standing in front of a vertical mirror at a distance of 3cm,if the mirror is rotated from is initial velocity through and angle of 50degree? 1.determine the size of the image of the man? 2.how far from the man is the image? 3.what is the shortest length of the ...
*Saturday, March 26, 2016 by Nobility*

**College Physics**

At what temperature is the root-mean-square speed of nitrogen molecules equal to the root-mean-square speed of hydrogen molecules at 126 oC? (Hint: The molar mass of hydrogen atoms is 1.008 g/mol and of nitrogen atoms is 14.007 g/mol. The molar mass of H2 is twice the molar ...
*Saturday, March 26, 2016 by Desperate Student*

**College Physics**

A welder using a tank of volume 1¡Ñ10−2m3 fills it with oxygen (with a molar mass of 32.0g/mol ) at a gauge pressure of 1.4¡Ñ105Pa and temperature of 37.0∘C. Find the initial mass of oxygen. R=8.314m3PaK-1mol-1. The answer¡¦s ...
*Saturday, March 26, 2016 by Desperate Student*

**College Physics**

If a certain amount of ideal gas occupies a volume 9.5 m3 with a pressure of 3.1 atm and temperature 5.4 oC on earth, what would be its volume on another planet, where the temperature is 5.3oC and the pressure is 7.4 atm ? The answer is in unit of m3
*Saturday, March 26, 2016 by Desperate Student*

**Physics**

A pan filled with hot food cools from 94°C to 86°C in 2minutes when the room temperaturs is at 20°C .How long will it take to cool from 71°C to 69°C ?
*Saturday, March 26, 2016 by Eddie*

**physics**

the age of jane and john add up to 25years.8years ago jane was twice as old as john.how old are they now?
*Saturday, March 26, 2016 by lucy*

**physics**

a handbag weighing 162N is carried by the students each holding the handle of the bag next to him. If each handle is inclined at 60° to the vertical, find the force on each students arm
*Saturday, March 26, 2016 by jay*

**Physics**

sound wave of frequency 166 Hz travels with a speed 332 ms−1 along positive x-axis in air. Each point of the medium moves up and down through 5.0 mm. Write down the equation of the wave and calculate the (i) wavelength, and (ii) wave number. How far are points which ...
*Saturday, March 26, 2016 by Komal*

**Physics**

The steady-state amplitude of a weakly damped forced oscillator is given by 2 2 2 2 2 2/1 0 0 [( ) 4 ] ( ) ω −ω + ω ω = b f a Depict it as a function of frequency and obtain expression for resonance frequency. Also obtain expression for peak value of ...
*Saturday, March 26, 2016 by Komal*

**Physics**

train moving with speed 72 km h−1 emits a whistle of frequency 600 Hz. A person is standing stationary on the platform. Calculate the frequency heard by the person if the train (i) approaches and (ii) recedes away from the listener.
*Saturday, March 26, 2016 by Komal*

**physics**

An electron is traveling at 1% the speed of light. what is its kinetic energy in joules? (Speed of light= 3x 10 to the exponent of 8 m/s) a. 4.000 x 10-18 (exponent of -18) b. 4.098 x 10 (exponent of -18) c. 4.098 x 10 (exponent of 10) d. 4.000 x 10 (exponent of 18)
*Saturday, March 26, 2016 by pub*

**physics**

A 2.00 kg ball moving to the right at 10.0 m/s makes an off-center collision with a stationary 3.00 kg ball. After the collision, the 2.00 kg ball is deflected upward at an angle of 30o from its original direction of motion and the 3.0 kg ball is moving at 4.0 m/s. Find the ...
*Friday, March 25, 2016 by brett*

**Physics**

Find The Potential Energy Of A Boy Mass 10kg Standing On A Building Floor Of 10 Metres Above Ground Level. 10*10*10 =1000
*Friday, March 25, 2016 by Davido*

**physics**

In a popular amusement park ride, a rotating cylinder of radius R = 3.10 m is set in rotation at an angular speed of 4.20 rad/s, as in the figure shown below. The floor then drops away, leaving the riders suspended against the wall in a vertical position. What minimum ...
*Friday, March 25, 2016 by jojo*

**physics**

Suppose a 1800-kg car passes over a bump in a roadway that follows the arc of a circle of radius 18.4 m as in the figure shown below. (a) What force does the road exert on the car as the car passes the highest point of the bump if the car travels at 9.24 m/s? (Neglect any ...
*Friday, March 25, 2016 by jojo*

**physics**

An air puck of mass m1 = 0.24 kg is tied to a string and allowed to revolve in a circle of radius R = 1.4 m on a frictionless horizontal table. The other end of the string passes through a hole in the center of the table, and a mass of m2 = 1.3 kg is tied to it (see the figure...
*Friday, March 25, 2016 by jojo*

**physics**

A rotating wheel requires 6.00 s to rotate 27.0 revolutions. Its angular velocity at the end of the 6.00-s interval is 97.0 rad/s. What is the constant angular acceleration (in rad/s) of the wheel?
*Friday, March 25, 2016 by jojo*

**physics**

A centrifuge in a medical laboratory rotates at an angular speed of 3,550 rev/min. When switched off, it rotates through 54.0 revolutions before coming to rest. Find the constant angular acceleration (in rad/s2) of the centrifuge.
*Friday, March 25, 2016 by jojo*

**Physics**

A Boy Of 20KG Climbs 10m.Take 10m/s. Calculate the workdone,
*Friday, March 25, 2016 by Anonymous*

**physics**

A satellite of mass 2500kg is orbiting the Earth in an elliptical orbit.At the farthest point from the Earth,its altitude is 3600km,while at the nearest point,it is 1100km.calculate the energy and angular momentm of the satellite and its speed at the aphelion and perihelion.
*Friday, March 25, 2016 by Anonymous*

**physics**

A satellite of mass 2500kg is orbiting the Earth in an elliptical orbit.At the farthest point from the Earth,its altitude is 3600km,while at the nearest point,it is 1100km.calculate the energy and angular momentm of the satellite and its speed at the aphelion and perihelion.
*Friday, March 25, 2016 by pawan kumar*

**physics**

what is the effective weight of a person of mass 60kg carried vertically up in a rocket with an
*Friday, March 25, 2016 by pawan kumar*

**physics**

a horizontal disk is rotating counter -clockwise about its axisof of symmetry at 14rps.Its rotational inertia with respect to its axis of symmetry is8kgm^2.A second disk,of
*Friday, March 25, 2016 by pawan*

**Physics**

Synthetic diamonds can be manufacated at pressures of 6.00 x 10 in power 4 atm . If we took 2.00 litres of gas at 1.00 atm and compressed it to a pressure of 6.00 x 10 in power 4 atm , what would the volume of that gas be ?
*Friday, March 25, 2016 by Midnight*

**physics**

A body falling from a high tower travels 40m in the last 2.71 sec of its fall to ground. What is the height of the tower?
*Friday, March 25, 2016 by gelee*

**physics**

A body falling from a high tower travels 40 m in the last 2.71sec of its fall to the ground. What is the height of the tower?
*Friday, March 25, 2016 by gelee*

**physics**

A 10-meter object is placed at a distance of 165 meters in front of a lens whose focal length is 50 meters. Which of the following describes the image formed?
*Thursday, March 24, 2016 by evensteven*

**physics**

please help The power rating of an electric motor which draws a current of 5 amperes from a 240-volt line is? a. 12.0 kW b. 1.2 kW c. 48.0 kW d. 4.8 kW
*Thursday, March 24, 2016 by pub*

**Physics**

Light is bent as it enters a tank of water from air. It is bent to a greater angle when it goes from air to a glass block. Calculate the angle of refraction of 30.0° light shines from water into ice. The indices of refraction for water and ice are 1.36 and 1.31, ...
*Thursday, March 24, 2016 by Tina*

**Physics**

Amotorvehicle of mass 1200kg is travelling along alevel road at 54km/hr.The breaks are then applied and the speed of the vehicle reduced to 18km/hr over adistance of 50M .if the afriction motion resistant is constant at 160N .calculate the effective braking force of the brakes...
*Thursday, March 24, 2016 by John*

**physics**

A helicopter of mass M is carrying a box of mass m at the end of a rope and is moving horizontally with constant acceleration 'a'. the acceleration due to gravity is 'g'. neglect air resistance. the rope is stretched out from the helicopter at a constant angle...
*Thursday, March 24, 2016 by Nikita Sukhwal *

**physics**

A pendulum has a period of 0.90 s on Earth. What is its period on a planet where the acceleration of gravity is about 0.29 that on Earth?
*Thursday, March 24, 2016 by ce*

**physics**

What is the speed of a transverse wave in a rope of length 1.90 m and mass 65.0 g under a tension of 465 N?
*Thursday, March 24, 2016 by Vio*

**Physics**

A child twirls a 0.15 kg mass attached to the end of a 15 cm long piece of string. He twirls the mass around at 2.4 revolutions per second in a vertical plane. Calculate the tension in the string when the mass is at the top of the circle.
*Thursday, March 24, 2016 by Anonymous*

**Physics**

how many revolutions per minute would a 5.8 metre radius ferris wheel need to make for the passenger to feel weightless at the topmost point? mass of passenger is 55.00 kg.
*Thursday, March 24, 2016 by Anonymous*

**Physics**

an electric motor accelerates a grinding wheel at constant acceleration from 112 rev/min to 295 rev/min in 13 seconds. how many revolutions did it make in this time?
*Thursday, March 24, 2016 by Anonymous*

**Physics!! Help**

someone swings a bucket of water in a vertical circle. Describe the water's motion to another person? or How would you? & also how to explain the motion of the water to them? How come the water didn't fall on the persons head? A: Centrifugal force causes the water to ...
*Thursday, March 24, 2016 by Tina*

**Physics**

A piece of copper of ball of mass 20g is placed in a copper calorimeter of mass 60g containing 50g of water at 30 degree Celsius ignoring heat losses, calculate the final steady temperature of the mixture. (SHC of water = 4.2j/g/k)
*Thursday, March 24, 2016 by Elahmadee *

**physics**

how much heat is required to warm 10 grams of ice from -10 celsius to 0 celsius? (specific heat of ice= 0.5 cal/g.C?)
*Thursday, March 24, 2016 by pub*

**Physics**

A material is formed into a long rod with a square cross section 0.31 cm on each side. When a 100 V voltage is applied across a 16 m length of the rod, a 4.6 A current is carried. What is the resistivity of the material? This is a rectangular wire rather than a cylindrical. I ...
*Thursday, March 24, 2016 by David*

**Physics**

Block B has a mass of 3.40kg and is moving to the left at a speed of 4.20m/s. Block A has a mass of 6.40kg and is moving to the right. The two blocks undergo a perfectly inelastic collision. What should the velocity of the Block A be in order to have the two blocks move to the...
*Wednesday, March 23, 2016 by Emily*

**Physics**

Block B has a mass of 2.20kg and is moving to the left at a speed of 2.30m/s. Block A has a mass of 2.70kg and is moving to the right. The two blocks undergo a perfectly inelastic collision. What should be the velocity of Block A in order to have the two blocks remain at rest ...
*Wednesday, March 23, 2016 by Emily*

**PHYSICS Centrifugal force**

someone swings a bucket of water in a vertical circle. Describe the water's motion to another person? or How would you? & also how to explain the motion of the water to them? How come the water didn't fall on the persons head? A: Centrifugal force causes the water to ...
*Wednesday, March 23, 2016 by Anonymous*

**PHYSICS**

With what maximum speed can an unsecured passenger stay in their seat on a Ferris wheel that has a diameter of 12 m. so, this happens when Fn is zero or mg = mv^2/r. v = sqrt(gr) so is it v=sqrt9.8 what would happen with the 12m
*Wednesday, March 23, 2016 by J*

**physics**

A 20.0 gram bullet exits the rifle at a speed of 985 m/s. The gun barrel is 0.80 m long. What was the force(N) during the rocket’s launch? (Hint: note the units of the bullet!)
*Wednesday, March 23, 2016 by Anonymous*

**Physics**

A 66.0 kg rider sitting on a 9.4 kg bike is riding along at 9.1 m/s in the positive direction. The rider drags a foot on the ground and slows down to 7.0 m/s still in the positive direction. What is the change in momentum of the rider and bike?
*Wednesday, March 23, 2016 by Andy*

**PHYSICS**

A SUPERSONIC FIGHTER JET FLYING HORIZONTALLW AT HEIGHT OF 4KM ABOVE THE GROUND AND AT A SPEED OF 400M/S FIRES A ROCKET VERTICALLY DOWNWARD. THE ROCKET IS RELEASED WITH AN INITIAL SPEED OF 80M/S CALCULATE THE TIME OF FLIGHT OF THE ROCKET AND THE HORIZONTAL DISTANCE FROM THE ...
*Wednesday, March 23, 2016 by Anonymous*

**physics**

3 equal charges each of of 2*10-6 C are fixed at three corners of an equilateral triangle ofsides 5 cm.find the column force experienced by one of the charge due to the other two
*Wednesday, March 23, 2016 by william *

**physics**

3 equal charges each of of 2*0.000001C are fixed at three corners of an equilateral triangle ofsides 5 cm.find the column force experienced by one of the charge due to the other two
*Wednesday, March 23, 2016 by william *

**Physics **

A grain bucket conveyor (grain leg) raises soybeans from the ground level up to the peak of its height, h= 150 ft. A bushel of soybean weight, W=60 lb/bu. The bucket elevator can deliver, Q= 120 bu/min, to the top spout. The motor shaft power to drive the elevator is 40 hp. ...
*Wednesday, March 23, 2016 by Max*

**Physics**

You are driving in your car, which has a mass of 980 kg, when you come across the bend shown in the picture below. This bend has a radius of curvature of 25.0 m and a maximum suggested speed of 35 km.h-1K
*Wednesday, March 23, 2016 by Kassa*

**Physics**

a uniform thin wire is bent into a semicircle of radius r, determine the coordinates of its center of mass with respect to an origin of coordinates at the center of the full circle
*Wednesday, March 23, 2016 by Melinda*

**physics**

A uniform thin wire is bent into a semicircle of radius r. Determine the coordinates of its center of mass with respect to an origin of coordinates at the center of the "full" circle. Because wire is uniform x (sub cm) = 0 mass=dm length=dl coordinates (x,y) = (r cox...
*Wednesday, March 23, 2016 by Melinda*

**physics**

Fifty liters of gas is kept at a temperature of 200 K and under pressure of 15 atm. The temperature of the gas is increased to 400 K. The pressure is decreased to 7.5 atm. What is the resulting volume of the gas?
*Wednesday, March 23, 2016 by Anonymous*

**Physics**

A 66-kg water skier is being pulled by a nylon (Young's modulus 3.7 x 109 N/m2) tow rope that is attached to a boat. The unstretched length of the rope is 20 m and its cross-section area is 2.8 x 10-5 m2. As the skier moves, a resistive force (due to the water) of ...
*Wednesday, March 23, 2016 by Jane*

**Physics**

An airplane is flying above an observer standing on the ground. At the moment it passes overhead, the observer judges by its apparent size that the airplane’s altitude is 30,000 feet. It takes 50 seconds for the plane, moving in a straight, horizontal line, to move ...
*Wednesday, March 23, 2016 by Anonymous*

**Physics**

An equilateral triangle initially has side length equal to 17 cm. Each vertex begins moving in a straight line towards the midpoint of the opposite side at a constant rate of 2.3 cm/s, continuously forming progressively smaller equilateral triangles until it disappears. At ...
*Wednesday, March 23, 2016 by Anonymous*

**physics**

A uniform thin wire is bent into a semicircle of radius r. Determine the coordinates of its center of mass with respect to an origin of coordinates at the center of the "full" circle. Because wire is uniform x (sub cm) = 0 mass=dm length=dl coordinates (x,y) = (r cox...
*Wednesday, March 23, 2016 by Melinda*

**PHYSICS**

Hooke's Law: 1.) If it takes 10 N to compress a spring 20cm, how much energy will be stored in the spring when it is stretched 50cm. ***Also, for ex: If I am doing work against a restoring force, say, doing work against gravity, what kind of force is the elastic force of a...
*Wednesday, March 23, 2016 by Angie*

**physics**

A horizontal, straight wire carrying 12 A current from east to west is in the earth's magnetic field B. At this place, B is parallel to the surface of the earth, points north and its magnitude is 0.04mT. Determine the Magnetic Force on 1 m length of wire. If mass of this ...
*Wednesday, March 23, 2016 by sanjay*

**PHYSICS**

A box slides down a frictionless, 10-meter, 30o incline. Calculate the gravitational potential energy at both the beginning and end of the motion. Calculate the work done by GRAVITY as the box slides down the incline. Compare this to the overall change in gravitational ...
*Wednesday, March 23, 2016 by Help! *

**physics**

A tank attached to an air compressor contains 20.0 litre of air at a temperature of 30¡ãc and guage pressure of 4.00¡Á10^5 pa. What is the mass of air, and what volume would it occupy at normal atmospheric pressure and 0¡ãc. Air is a ...
*Wednesday, March 23, 2016 by Chinonso*

**Physics**

A student on a piano stool rotates freely with an angular speed of 3.07 rev/s. The student holds a 1.38 kg mass in each outstretched arm, 0.759 m from the axis of rotation. The combined moment of inertia of the student and the stool, ignoring the two masses, is 4.72 kg·...
*Tuesday, March 22, 2016 by Mackenzie*

**Physics **

An electric kettle has a power of 1.2kw. How long will it take to heat 3 kg of water to the from 20¡ãC to 100¡ãC?
*Tuesday, March 22, 2016 by John*

**Physics**

How would I express the magnetic force in terms of Fmax if the angle between the velocity and the magnetic field direction is 10 degrees? I know the magnetic force equation is F=qVBsin(theta), but how do I put it in terms of maximum force (Fmax)?
*Tuesday, March 22, 2016 by Savannah*

**Physics **

A box slides down a frictionless, 10-meter, 30o incline. Calculate the gravitational potential energy at both the beginning and end of the motion. Calculate the work done by GRAVITY as the box slides down the incline. Compare this to the overall change in gravitational ...
*Tuesday, March 22, 2016 by Julie*

**Physics**

Is this right? When a 5 kg box is lifted 3 meters from the ground, calculate the gravitational potential energy stored in the box. Calculate the work done by a Force to lift the box at a constant speed. Compare this answer to the amount of gravitational potential energy stored...
*Tuesday, March 22, 2016 by A*

**physics**

Two stars with masses 2.75 x 10^30 kg and 5.92 x 10^30 kg form a binary system. If the two stars have an average separation of 7.28×10^8 km, compute the magnitude of the gravitational force in Newtons between the stars. Express your result in scientific notation and to ...
*Tuesday, March 22, 2016 by lizbeth*

**Physics**

Do you think the sun's gravity is greater or less than that of all the other planets?
*Tuesday, March 22, 2016 by Demyion*

**Physics**

As a particle moves along the x axis it is acted upon by a single conservative force given by Fx = (20 - 4,0x) N where x is in m. The potential energy associated with this force has the value +30 J at the origin 9x =0). What is the value of the potential energy at x = 4.0 m?
*Tuesday, March 22, 2016 by Beverly*

**Physics**

A single conservative force Fx = (6.0x - 12) (x is in m) acts on a particle moving along the x axis. The potential energy associated with this force is assigned a value of + 20 J at x = 0. What is the potential energy at x = 3.0 m?
*Tuesday, March 22, 2016 by Beverly*

**Physics**

A 63-kg ice-skater glides with a speed of 10 m/s toward a 14-kg sled at rest on the ice. The ice-skater reaches the sled and holds on to it. The ice-skater and the sled then continue sliding in the same direction in which the ice-skater was originally skating. What is the ...
*Tuesday, March 22, 2016 by Emily*

**physics**

Radio waves of wavelength 163 m from a galaxy reach a radio telescope by two separate paths as shown in the figure below. One is a direct path to the receiver, which is situated on the edge of a tall cliff by the ocean, and the second is by reflection off the water. As the ...
*Tuesday, March 22, 2016 by Anonymous urgent*

**Physics**

A sports car is accelerating up a hill that rises 17.0° above the horizontal. The coefficient of static friction between the wheels and the road is µs = 0.79. It is the static frictional force that propels the car forward. (a) What is the ...
*Tuesday, March 22, 2016 by Anonymous*

**Physics**

A 64.8 kg ice skater is skating along in a straight line (in the positive direction) at 9.2 m/s when he bends down and scoops up his 24.4 kg doggy sitting still on the ice. What will be the new velocity of the dog-n-skater?
*Tuesday, March 22, 2016 by Emily*

**physics**

Which is the vector quantity that describes the shortest path between two points?
*Tuesday, March 22, 2016 by maria*

**physics**

You see some management students getting drunk at 1 PM in the quad. (Yes, this is an early wake up call for them.) You decide to tie a 2.00 daN water balloon on the end of a 1.00 m long light rope and start swinging it horizontally. The rope from your hand to the water balloon...
*Tuesday, March 22, 2016 by BOB*

**physics**

A tank attached to an air compressor contains 20.0 litre of air at a temperature of 30¡ãc and guage pressure of 4.00¡Á10^5 pa. What is the mass of air, and what volume would it occupy at normal atmospheric pressure and 0¡ãc. Air is a ...
*Tuesday, March 22, 2016 by Chinonso*

**Physics**

What is the average useful power output of a person who does 5.90×106 J of useful work in 7.90 h? I got 207 W Working at this rate, how long will it take this person to lift 2400 kg of bricks 1.30 m to a platform? (Work done to lift his body can be omitted because it is ...
*Tuesday, March 22, 2016 by Emily Ann*

**physics**

a projectile is launched outward at an angle theta above an incline plane elevated an angle alpha above the horizon. when the projectile hits the plane it is moving horizontally. prove for this case that the angle theta must satisfy the following relations.
*Tuesday, March 22, 2016 by Diana*

**Physics**

The figure (Figure 1) shows a model of a crane that may be mounted on a truck.A rigid uniform horizontal bar of mass m1 = 80.0 kg and length L = 5.30 m is supported by two vertical massless strings. String A is attached at a distance d = 1.90 m from the left end of the bar and...
*Tuesday, March 22, 2016 by Shelby*

**physics**

A 9-kg block is held by a pulley system shown in fig. What force must the person exert in the following cases: a) to hold the block at rest. b) to lower it at 2m/s. c) to raise it with an acceleration of 0.5 m/s2? Ignore the mass of small pulley. Answer Thi
*Tuesday, March 22, 2016 by Anonymous*

**physics**

Driving down Highway 401 in Ontario, it had rained and stopped raining by the time I came to the freezing rain on the highway. I knew there was a problem when the cars in front of me started to fly off the highway at the curve in the road. Assume the curve in the road is ...
*Tuesday, March 22, 2016 by Tom*

**Physics**

What is the average useful power output of a person who does 5.90×106 J of useful work in 7.90 h?
*Tuesday, March 22, 2016 by Emily Ann*

**Physics**

Suppose under the certain conditions, the maximum force of friction that could act on a certain car was 3.35*10^3 N. The mass of the car is 857kg. What is the maximum possible centripetal acceleration of the car going around a bend? I know the equation for this is a=(4piR)/(T^...
*Tuesday, March 22, 2016 by Em*

**physics**

Radio waves of wavelength 163 m from a galaxy reach a radio telescope by two separate paths as shown in the figure below. One is a direct path to the receiver, which is situated on the edge of a tall cliff by the ocean, and the second is by reflection off the water. As the ...
*Tuesday, March 22, 2016 by Anonymous urgent*

**physics**

A student holds a laser that emits light of wavelength 641.5 nm. The laser beam passes though a pair of slits separated by 0.400 mm, in a glass plate attached to the front of the laser. The beam then falls perpendicularly on a screen, creating an interference pattern on it. ...
*Monday, March 21, 2016 by James urgent*

**physics**

Assuming that the equation Ephoton, final = Ephoton, initial/1 + Ephoton, initial/mec2 (1 − cos θ) can be approximately applied at all scattering angles θ, what is the minimum energy of a scattered X-ray photon if the incident X-ray energy is 76 keV? What is ...
*Monday, March 21, 2016 by m*

**Physics**

An astronaut exploring a distant solar system lands on an unnamed planet with radius 3,860 km. When the astronaut jumps upward with an initial speed of 3.5 m/s, she rises to a height of 0.62 m. What is the mass of the planet to within 0.1%?
*Monday, March 21, 2016 by suveer*

**physics**

Soft tissue has a linear attenuation coefficient in the range of μ = 0.35 cm−1 at 30 keV and μ = 0.16 cm−1 at 100 keV. For this problem we use μ = 0.21 cm−1, which applies at around 50 keV incident X-ray energy. (a) What fraction of X-ray ...
*Monday, March 21, 2016 by mar*

**PHYSICS? **

1300 kg car rounds a banked curve of radius= 50m. If car traveling at 75 km/h and the coefficient of static friction between the tire and road is 0.45 ... 1.) what is the minimum angle of the bank needed to keep the car in the turn? 2.) If the car changes tires, which ...
*Monday, March 21, 2016 by Dina*

**Physics**

With what maximum speed can an unsecured passenger stay in their seat on a Ferris wheel that has a diameter of 12 m.
*Monday, March 21, 2016 by Jules*

**Physics**

3)-A 9-kg block is held by a pulley system shown in fig. What force must the person exert in the following cases: a) to hold the block at rest. b) to lower it at 2m/s. c) to raise it with an acceleration of 0.5 m/s2? Ignore the mass of small pulley.
*Monday, March 21, 2016 by Simon*