Tuesday

September 27, 2016
**Physics**

A costant force F is aplied to a crate of mass 25kg to move it upward along a frictionless inclined plane.when it reaches point A,its speed is 12 m.s-1 and 10,8 m,s-1 when it reaches point B which is 3.5m futher up the incline

*Tuesday, March 31, 2015 by Hlengiwe*

**Physics**

At an intersection a car of mass 900kg traveling east collides with a pick up truck of mass 1800kg that is traveling North. Two vehicles stick together as a result of the collision, and after collision, the wreckage is sliding at 16m/sec in the direction 24 degrees East of ...

*Tuesday, March 31, 2015 by anne*

**physics**

A copper atom has 29 electrons revolving around the nucleus. A copper ball has 4x10^23 atoms. What fraction of the electrons be removed to give the ball a charge of +9.6uC?

*Tuesday, March 31, 2015 by David *

**Physics**

The force acts on a 1.7kg object whose initial speed is 0.44m/s and initial position is x = 0.27. Find the speed of the object when it is a the location x = 0.99m?

*Tuesday, March 31, 2015 by Anonymous*

**physics**

At 7.15 cents per kilowatt-hour, what does it cost to leave a 75.0W light burning 24.0 hours a day?

*Tuesday, March 31, 2015 by Jaimi*

**Physics **

Determine the amount of energy required to raise the temperature of 250 grams of steel from a temperature of 15 oC to a temperature of 40 oC . The specific heat of steel is 0.11 cal/gram oC.

*Monday, March 30, 2015 by Melissa *

**physics**

In 1993, Cuban athlete Javier Sotomayor set the world record for the high jump. the gravitational potential energy associated with Sotomayor's jump was 1970 J. Sotomayor's mass was 82.0 kg. How high did Sotomayor Jump?

*Monday, March 30, 2015 by Helena*

**physics**

a window air conditioner is estimated to have a cost of operation of $50 per 30 days. this is based on the assumption that the air conditioner will run half of the time and that electricity costs $.090 per kWh. determine how much current the air conditioner will take from a ...

*Monday, March 30, 2015 by allan*

**Physics**

A charged capacitor, C = 40 micro F, is connected to a resistor, 120 ohms. How much time will elapse until the voltage falls to 25% of its original (max) value? im not even sure what equation to use for this, so if someone could help me to figure that out it wou ld be greatly ...

*Monday, March 30, 2015 by Amber*

**physics**

A 0.205 kg bird flying along at 7.8 m/s sees a 0.029 kg insect heading straight toward it with a speed of 15 m/s (as measured by an observer on the ground, not by the bird). The bird opens its mouth wide and enjoys a nice lunch. What is the bird's speed immediately after ...

*Monday, March 30, 2015 by Kristin*

**physics **

A freshman smart alek lips off onces too often! The assistant principle loses her cool and grabs the 38.0kg punk by the hair- swinging him in a vertical circle of radius 1.20m! if the freshman is moving at 6.30m/s at the bottom of the swing, calculate: A) the tensions in the ...

*Monday, March 30, 2015 by greoge*

**physics**

The principle of conservation of heat energy states that

*Monday, March 30, 2015 by temmyth*

**PHYSICS NEED HELP ASAP**

A freshman smart alek lips off onces too often! The assistant principle loses her cool and grabs the 38.0kg punk by the hair- swinging him in a vertical circle of radius 1.20m! if the freshman is moving at 6.30m/s at the bottom of the swing, calculate: A) the tensions in the ...

*Monday, March 30, 2015 by greoge*

**physics**

a 60-kilogram astronaut floating in space outside the capsule throws his 0.50-kilogram hammer such that it moves with a speed of 10 m/s relative to the capsule. what happens to the astronaut?

*Monday, March 30, 2015 by Ted*

**physics**

a 50g slug is shot from a rifle at 900m/s a) what is the KE of the slug? b) how much work is done on the slug if it starts from rest?

*Monday, March 30, 2015 by joe*

**Physics**

So, "a uniform steel rod of length 1.20 meters and mass 6.40 kg has attached to each end a small ball of mass 1.06 kg. The rod is constrained to rotate in a horizontal plane about a vertical axis through its midpoint." There's more to the question, but the only ...

*Monday, March 30, 2015 by Nora*

**physics**

A merry-go-round rotates at the rate of 0.16 rad/s with a(n) 43.0 kg man standing at a point 2.4 m from the axis of rotation. What is the new angular speed when the man walks to a point 0.64 m from the center? Assume that the merry-go-round is a solid 5.99 ×102 kg ...

*Monday, March 30, 2015 by Jalen*

**physics**

Part 2: Complete the following math problems by using the Law of Momentum Conservation. Formulas: i. Momentum = (mass) * (velocity) ii. Impulse = (Applied force) * (time) and Impulse = Change in Momentum iii. Applied Force = (Change in Momentum) / (time) iv. For multiple ...

*Sunday, March 29, 2015 by Sarah*

**physics**

A 8.0 kg shell leaves a 2.0 x 103 kg cannon, at a speed of 4.0 x 102 m/s. What is the recoil speed of the cannon?

*Sunday, March 29, 2015 by Abby*

**Physics**

A uniform disk of radius 0.5 m and mass 3.9 kg is rotating about its center of mass. Its moment of inertia about its center of mass is I=(1/2)mR^2. Its angular velocity as a function of time is given by (t)=7kt^6/t1^7 where k = 3.8 rad and t1= 5 s. Find the magnitude of the ...

*Sunday, March 29, 2015 by Esha*

**Physics**

A motorist is trying to loosen a stubborn lugnut by standing on the end of a wrench. The wrench is inclined 33.8 degrees above the horizontal and the distance from the center of the nut to the end of the wrench is 0.60 m. Assuming the motorist does not bounce up and down on ...

*Sunday, March 29, 2015 by Michelle*

**Physics**

A cup of coffee is on a table in an airplane flying at a constant altitude and a constant velocity. The coefficient of static friction between the cup and the table is 0.420 . Suddenly, the plane accelerates forward, its altitude remaining constant. What is the maximum ...

*Sunday, March 29, 2015 by Kristyn*

**Physics**

The drawing (not to scale) shows one alignment of the sun, earth, and moon. The gravitational force that the sun exerts on the moon is perpendicular to the force that the earth exerts on the moon. The masses are: mass of sun=1.99 × 1030 kg, mass of earth=5.98 × ...

*Sunday, March 29, 2015 by Kristyn*

**Physics**

An eagle is flying horizontally at 5.8 m/s with a fish in its claws. It accidentally drops the fish. (a) How much time passes before the fish's speed doubles? (b) How much additional time would be required for the speed to double again?

*Sunday, March 29, 2015 by KS*

**physics**

A proton is acted on by an uniform electric field of magnitude 233 N/C pointing in the positive x direction. The particle is initially at rest. (a) In what direction will the charge move? (b) Determine the work done by the electric field when the particle has moved through a ...

*Sunday, March 29, 2015 by mathew*

**physics**

a body projected with velocity 30m/s an angle 30¡ã with horizontal maximum height attained by he object is.........?

*Sunday, March 29, 2015 by yogesh*

**physics**

(a) A charged particle accelerates as it moves from location A to location B. If V A = 170 V and V B = 210 V, what is the sign of the charged particle? positive negative (b) A proton gains electric potential energy as it moves from point 1 to point 2. Which of the following is...

*Sunday, March 29, 2015 by mathew*

**physics**

Two parallel conducting plates are separated by 10.0 cm, and one of them is taken to be at zero volts. (a) What is the electric field strength between them, if the potential 8.50 cm from the zero volt plate (and 1.50 cm from the other) is 450 V? kV/m (b) What is the voltage ...

*Sunday, March 29, 2015 by mathew*

**Physics**

a red car and a green car move toward each other in adjacent lanes and parallel to an x axis. At time t = 0, the red car is at xr = 0 and the green car is at xg = 212 m. If the red car has a constant velocity of 23.0 km/h, the cars pass each other at x = 44.2 m. On the other ...

*Sunday, March 29, 2015 by Mike*

**physics**

An ideal gas has an initial volume of 500 cm3 , an initial temperature of 20◦C, and an initial pressure of 2 atm. What is its final pressure if the volume is allowed to expand to 1000 cm3 while the temperature increases to 60◦C?

*Sunday, March 29, 2015 by khalifah*

**physics**

If 50 g of ice at −5 ◦C is mixed into 300 g of water at 60◦C in a completely insulated container, what is the final equilibrium temperature of the water? Why did we insist on the container being completely insulated?

*Sunday, March 29, 2015 by bri*

**physics**

A spherical buoy of radius 25 cm and mass 8 kg sits in sea water of density 1025 kg/m3 . At low tide its anchoring chains have got tangled. What is the maximum tension force this chain may have to withstand at high tide? Assume calm conditions.

*Sunday, March 29, 2015 by bri*

**physics**

1) What average power is required for a runner with a mass of 85 kg to reach a speed of 8 m/s from a stationary start during a time of 2 s? 2) A 1000 kg car travels east at 30 m/s and collides with a 3400 kg truck travelling south at 20 m/s. After the collision the two ...

*Sunday, March 29, 2015 by k*

**physics**

A simple harmonic oscillator executes motion whose amplitude is 0.20 m and it completes 60 oscillations in 2 minutes. i) Calculate its time period and angular frequency. ii) If the initial phase is 45°, write expressions for instantaneous displacement, velocity and ...

*Sunday, March 29, 2015 by meenu*

**physics dicussion question**

is there any physics teachers available to help right now?

*Saturday, March 28, 2015 by abs*

**Medical physics**

1.A hypodermic needle of lenght 0.020m and inner radius 3.0 x10^-4 is used to force water at 20 degree celcious into the air at a flow rate of 1.0 x10^-7m^2 s-1 (a) what is the average velocity in the needle?(assume laminar flow), (b) what is the pressure drop necessary to ...

*Saturday, March 28, 2015 by JAMES*

**physics**

The steel I-beam in the drawing has a weight of 1.75 × 103 N and is being lifted at a constant velocity. The angles are at 70 degrees. What is the tension in each cable attached to its ends?

*Saturday, March 28, 2015 by Kristyn*

**physics**

A cup of coffee is on a table in an airplane flying at a constant altitude and a constant velocity. The coefficient of static friction between the cup and the table is 0.420 . Suddenly, the plane accelerates forward, its altitude remaining constant. What is the maximum ...

*Saturday, March 28, 2015 by Kristyn*

**physics**

A 46.2-kg crate rests on a level floor at a shipping dock. The coefficients of static and kinetic friction are 0.566 and 0.440, respectively. What horizontal pushing force is required to (a) just start the crate moving and (b) slide the crate across the dock at a constant speed?

*Saturday, March 28, 2015 by Kristyn*

**physics**

The gravitational force that the sun exerts on the moon is perpendicular to the force that the earth exerts on the moon. The masses are: mass of sun=1.99 × 1030 kg, mass of earth=5.98 × 1024 kg, mass of moon=7.35 × 1022 kg. The distances shown in the drawing ...

*Saturday, March 28, 2015 by Kristyn*

**physics**

A criminal is escaping across a rooftop and runs off the roof horizontally at a speed of 4.6 m/s, hoping to land on the roof of an adjacent building. Air resistance is negligible. The horizontal distance between the two buildings is D, and the roof of the adjacent building is ...

*Saturday, March 28, 2015 by Kristyn*

**physics**

A golfer imparts a speed of 25.8 m/s to a ball, and it travels the maximum possible distance before landing on the green. The tee and the green are at the same elevation. (a) How much time does the ball spend in the air? (b) What is the longest "hole in one" that the...

*Saturday, March 28, 2015 by Kristyn*

**physics**

A flat (unbanked) curve on a highway has a radius of 220m. A car rounds the curve at a speed of 25m/s. What is the minimum coefficient of friction that will prevent sliding?

*Saturday, March 28, 2015 by Shelby *

**physics**

An unstretched ideal spring hangs vertically from a fixed support. A 0.4 kg object is then attached to the lower end of the spring. The object is pulled down to a distance of 35cm below the unstretched position and released from rest at t=0s. A graph of the subsequent vertical...

*Saturday, March 28, 2015 by Helly*

**physics**

Calculate the net charge on a substance consisting of a combination of 6.7 ✕ 10^13 protons and 3.0 ✕ 10^13 electrons.

*Saturday, March 28, 2015 by Makenzie*

**physics**

A golfer imparts a speed of 25.8 m/s to a ball, and it travels the maximum possible distance before landing on the green. The tee and the green are at the same elevation. (a) How much time does the ball spend in the air? (b) What is the longest "hole in one" that the...

*Saturday, March 28, 2015 by Kristyn*

**physics**

The gravitational force that the sun exerts on the moon is perpendicular to the force that the earth exerts on the moon. The masses are: mass of sun=1.99 × 1030 kg, mass of earth=5.98 × 1024 kg, mass of moon=7.35 × 1022 kg. The distances shown in the drawing ...

*Saturday, March 28, 2015 by Kristyn*

**physics**

A golfer imparts a speed of 25.8 m/s to a ball, and it travels the maximum possible distance before landing on the green. The tee and the green are at the same elevation. (a) How much time does the ball spend in the air? (b) What is the longest "hole in one" that the...

*Saturday, March 28, 2015 by Kristyn*

**Medical physics**

1.A hypodermic needle of lenght 0.020m and inner radius 3.0 x10^-4 is used to force water at 20 degree celcious into the air at a flow rate of 1.0 x10^-7m^2 s-1 (a) what is the average velocity in the needle?(assume laminar flow), (b) what is the pressure drop necessary to ...

*Saturday, March 28, 2015 by JAMES*

**Physics**

A particle starts from the origin at t = 0 with an initial velocity of 4.8m/s along the positive x axis.If the acceleration is (-2.5 i^ + 4.3 j^)m/s2, determine (a)the velocity and (b)position of the particle at the moment it reaches its maximum x coordinate Express your ...

*Saturday, March 28, 2015 by Jackson*

**physics**

mercury rotates about its own axis once every 58.6 Earth days. a satellite orbits mercury once every murcurian day. how high is this satellite above mercury's surface? mass of mercury = 3.2x10^23 kg. the radius of mercury is 2400km.

*Saturday, March 28, 2015 by khalifah*

**mathematical physics**

Obtain the temperature distribution u(x,t) in a literally insulated rod of length L if both ends on the road are kept at 0°c and the initial temperature distribution in the bar is: u( x, 0 ) = 6sin[πx/L]

*Saturday, March 28, 2015 by gourav*

**mathematical physics**

Separate the following partial differential equation into a set of three ODEs by the method of separation of variables: d^2u/dt^2 =c^2,[d^2u/dr^2+1/r du/dr+1/r^2 d^2u/d theeta^2]

*Saturday, March 28, 2015 by gourav*

**mathematical physics**

Show that :(I) u = e^xsiny is a solution of Laplace's equation. (ii) u = x^2+t^2 is a solution of the wave equation.

*Saturday, March 28, 2015 by gourav*

**mathematical physics**

A series circuit consists of a resister with R = 200 ohm, an inductor with L = 1H, a capacitor with C = 0.002F, and a 12V battery. If the initial charge and current are both 0, find the charge and current at time t.

*Saturday, March 28, 2015 by gourav*

**mathematical physics**

Solve the initial value problem. d^2x/dt^2+2dx/dt-3x =0, x(2π) = 1, x(2π) = 13

*Saturday, March 28, 2015 by gourav*

**mathematical physics**

Show that : vector del(r^2) = 2vector r

*Saturday, March 28, 2015 by gourav*

**mathematical physics**

For any two vectors u and v show that : ( Vector u.vector v )^2 = [(vector u× vector v)×vector v ].vector u = u^2v^2

*Saturday, March 28, 2015 by gourav *

**Physics**

A person pushes on a 56-kg refrigerator with a horizontal force of -260 N; the minus sign indicates that the force points in the -x direction. The coefficient of static friction is 0.58. (a) If the refrigerator does not move, what are the magnitude and direction of the static ...

*Friday, March 27, 2015 by Physics2hard4me*

**Physics**

At the train station, you notice a large horizontal spring at the end of the track where the train comes in. This is a safety device to stop the train so that it will not plow through the station if the engineer misjudges the stopping distance. While waiting, you wonder what ...

*Friday, March 27, 2015 by Martez *

**Algebra 1**

A physics student stands on top of a hill that has an elevation of 56 meters. He throws a rock and it goes up into the air and then falls past him and lands on the ground below. The path of the rock can be modeled by the equation - y=-0.04x^2+1.3x+56 where x is the horizontal ...

*Friday, March 27, 2015 by Steve*

**mathematical physics**

Obtain the temperature distribution u(x,t) in a laterally insulated rod of length L if both ends on the road are kept at 0°c and the initial temperature distribution in the bar is: u(x,0) = 6sin[πx/L]

*Friday, March 27, 2015 by gourav *

**mathematical physics**

Show that : (I) u = e^xsiny is a solution of Laplace's equation. (ii) u= x^2+t^2 is a solution of the wave equation.

*Friday, March 27, 2015 by gourav *

**mathematical physics**

Solve the initial initial value problem d^2x/dt^2+2DX/dt-3x =0, x(2π) = 0, x(2π) = 13

*Friday, March 27, 2015 by gourav *

**PHYSICS**

A swimmer, capable of swimming at a speed of 1.24 m/s in still water (i.e., the swimmer can swim with a speed of 1.24 m/s relative to the water), starts to swim directly across a 2.24-km-wide river. However, the current is 0.553 m/s, and it carries the swimmer downstream. (a) ...

*Friday, March 27, 2015 by Physics2hard4me*

**physics**

A 2.50m -long, 450g rope pulls a 10.0kg block of ice across a horizontal, frictionless surface. The block accelerates at 2.50m/s2 . How much force pulls forward on the rope?

*Friday, March 27, 2015 by Matt*

**Physics **

Cart A has a mass of 10kg and is moving towards cart B at a speed of 15 m/s. If cart B is moving towards cart A with a speed of 5 m/s, what mass must Cart B have to stop both carts upon collision?

*Thursday, March 26, 2015 by Danielle *

**Physics**

You drop a rock from a 300-meter cliff. How long will it take to reach the ground? Assume it has no significant air resistance

*Thursday, March 26, 2015 by Matt*

**Physics**

If a ball is launched into the air vertically with a velocity of 20 m/sec, how fast will it be moving after two seconds? (The gravity's acceleration is rounded to 10 m/sec/sec.)

*Thursday, March 26, 2015 by Tom*

**PHYSICS HELP **

Suppose the aliens watching the show are on the surface of Mars. Mass of Mars: 6.42 x 10^23 kg Radius of Mars: 3.394 x 10^6 m Calculate; A) the weight of a 40.0 kg alien on Mars B) the weight of 40.0kg alien on earh Earth-sun distance:1.50x10^11m Mars-sun distance: 2.28 x10^11...

*Thursday, March 26, 2015 by Maddie *

**physics**

a force of 150N does 3.40kj of work over a displacement of 25.0m. what is the angle between the force vector and the displacement vector?

*Thursday, March 26, 2015 by ben*

**physics**

You're in an airplane that flies horizontally with speed 830km/h (230m/s ) when an engine falls off. Neglecting air resistance, assume it takes 35s for the engine to hit the ground. Find the height of airplane. Find the horizontal distance that the aircraft engine falls.

*Thursday, March 26, 2015 by Maria*

**Physics**

It took a force of 262. N to pull a crate weighing 765 N across the floor. The work done was 3500. J. How far was the crate moved?

*Thursday, March 26, 2015 by Anonymous*

**Physics**

An 78.9 kg person carries a 23 N package up a flight of stairs. The vertical height of the stairs is 23.8 m. How much work is done?

*Thursday, March 26, 2015 by Anonymous*

**Physics**

A 1500kg car is travelling around a large roundabout of radius 40m at a constant speed of 50kmh-1. Calculate the time it takes to go halfway aound the roundabout. Just wondering which equation I should use. Thanks

*Thursday, March 26, 2015 by Mandy*

**PHYSICS**

A diver leaves a 3-m board on a trajectory that takes her 2.7m above the board and then into the water 2.9m horizontally from the end of the board.At what speed did she leave the board?At what angle did she leave the board?

*Thursday, March 26, 2015 by PLS HELP!!*

**Physics**

A diver leaves a 3-m board on a trajectory that takes her 2.8m above the board and then into the water 2.7m horizontally from the end of the board.At what speed and angle did she leave the board?

*Thursday, March 26, 2015 by Sarah*

**Physics**

You can run 8.8m/s,20% faster than your brother. How much head start should you give him in order to have a tie race over 110m?please help:(

*Thursday, March 26, 2015 by Sarah*

**Physics **

The heating element in a George foreman grill is plugged into a 120-V wall socket, and 1 C of charge passes through it every 0.09 s. What is its power output, and what is the electrical energy being converted into?

*Wednesday, March 25, 2015 by Emily *

**physics**

A penny is dropped from the top of a building 310 m high. Ignoring air resistance, if the penny falls straight down, with what speed would it hit the ground?

*Wednesday, March 25, 2015 by Nick*

**Physics **

A force of 112 N acts on 35 kg box which moves at a steady speed across the floor. The force is directed 40 degrees above the ground. How to state Newton's second law using x components and y components? x: -Fa(cos40) -Ff=ma and y: -Fa(sin40)+Fn-Fg=0? How do you calculate ...

*Wednesday, March 25, 2015 by Alice*

**Physics **

The heating element in a George foreman grill is plugged into a 120-V wall socket, and 1 C of charge passes through it every 0.09 s. What is its power output, and what is the electrical energy being converted into?

*Wednesday, March 25, 2015 by Emily *

**physics**

Two converging lenses are separated by 25.0 cm. The focal length of each lens is 17.0 cm. An object is placed 35.0 cm to the left of the lens that is on the left. Determine the final image distance relative to the lens on the right.

*Wednesday, March 25, 2015 by britney*

**physics**

Two stones are thrown simultaneously, one straight upward from the base of a cliff and the other straight downward from the top of the cliff. The height of the cliff is 5.28 m. The stones are thrown with the same speed of 9.33 m/s. Find the location (above the base of the ...

*Wednesday, March 25, 2015 by Anonymous*

**physics**

At an instant when a soccer ball is in contact with the foot of the player kicking it, the horizontal or x component of the ball's acceleration is 930 m/s2 and the vertical or y component of its acceleration is 960 m/s2. The ball's mass is 0.34 kg. What is the ...

*Wednesday, March 25, 2015 by Kristyn*

**physics**

A fire hose ejects a stream of water at an angle of 31.7 ° above the horizontal. The water leaves the nozzle with a speed of 29.2 m/s. Assuming that the water behaves like a projectile, how far from a building should the fire hose be located to hit the highest possible fire?

*Wednesday, March 25, 2015 by Kristyn*

**Physics**

In the figure below, a block of mass m = 14 kg is released from rest on a frictionless incline angled of angle θ = 30°. Below the block is a spring that can be compressed 2.0 cm by a force of 270 N. The block momentarily stops when it compresses the spring by 4.6 cm. ...

*Wednesday, March 25, 2015 by Anonymous*

**physics**

A slab of wood with mass m=1.7kg floats 78% submerged.the density of water is 1000kg/m.what is the density of the wood?

*Wednesday, March 25, 2015 by eunice*

**physics**

A solid ball with a mass m=0.53kg floats in a tank of water.The ball is made of material with a density of 400kg/m^3.The density of water is 1000kg/m^3.what fraction of the ball is below waterline?

*Wednesday, March 25, 2015 by eunice*

**physics**

A fire hose ejects a stream of water at an angle of 31.7 ° above the horizontal. The water leaves the nozzle with a speed of 29.2 m/s. Assuming that the water behaves like a projectile, how far from a building should the fire hose be located to hit the highest possible fire?

*Wednesday, March 25, 2015 by Kristyn*

**physics **

a 20newton object Is pulled along a horizontal surface at a constant velocity by a 30N force. What is the coefficient of friction

*Wednesday, March 25, 2015 by Christine*

**physics**

Question Part Points Submissions Used 1 –/2.35 0/100 Total –/2.35 ... Janet wants to find the spring constant of a given spring, so she hangs the spring vertically and attaches a 0.53 kg mass to the spring's other end. If the spring stretches 3.9 cm from its ...

*Wednesday, March 25, 2015 by hannah*

**physics**

A mother rocket fired from the ground last year’s eve ejects 25% of its mass 2.0 at the at the rate if so m/s in the first second of its flight. Find the initial acceleration of the mother rocket.

*Wednesday, March 25, 2015 by ella*

**Physics**

A ball is attached to one end of a wire, the other end being fastened to the ceiling. The wire is held horizontal, and the ball is released from rest (see the drawing). It swings downward and strikes a block initially at rest on a horizontal frictionless surface. Air ...

*Wednesday, March 25, 2015 by Sia*

**Physics **

A 10kg suitcase is placed on a horizontal conveyor belt the top of which moves to the right. The coefficient of static friction between the belt and box is µs = 0.5 and that of kinetic friction is µk = 0.3. a) Sketch a free body diagram for the suitcase, showing ...

*Wednesday, March 25, 2015 by Jim*

**physics**

A mother rocket fired from the ground last year’s eve ejects 25% of its mass at the at the rate if so m/s in the first second of its flight. Find the initial acceleration of the mother rocket.

*Wednesday, March 25, 2015 by ella*

**Physics**

You're an investigator for the National Transportation Safety Board, examining a subway accident in which a train going at 80km/h collided with a slower train traveling in the same direction at 20km/h . Your job is to determine the relative speed of the collision, to help ...

*Wednesday, March 25, 2015 by Robert*

**physics**

Starting from home, you bicycle 22km north in 2.3h and then turn around and pedal straight home in 1.3h . What are your (a) displacement at the end of the first 2.3h , (b) average velocity over the first 2.3h , (c) average velocity for the homeward leg of the trip, (d) ...

*Wednesday, March 25, 2015 by tendi*

**physics**

Two strings are vibrating at the same frequency of 113 Hz. After the tension in one of the strings is decreased, an observer hears two beats each second when the strings vibrate together. Find the new frequency in the adjusted string.

*Wednesday, March 25, 2015 by romal *

**physics**

A golfer imparts a speed of 25.8 m/s to a ball, and it travels the maximum possible distance before landing on the green. The tee and the green are at the same elevation. (a) How much time does the ball spend in the air? (b) What is the longest "hole in one" that the...

*Wednesday, March 25, 2015 by Kristyn*