Saturday

April 18, 2015

April 18, 2015

**Recent Homework Questions About Physics**

**Physics**

Water flows through a 4 cm diameter garden hose at a velocity of 2 m/s. What is the velocity of the water if a nozzle is used with a diameter of 0.5 cm?
*Friday, April 17, 2015 at 11:53pm*

**Physics**

Suppose 2100 J of heat are added to 3.3 mol of argon gas at a constant pressure of 120 kPa. (Assume that the argon can be treated as an ideal monatomic gas.) A) Find the change in internal energy. B) Find the change in temperature for this gas. C)Calculate the change in volume...
*Friday, April 17, 2015 at 9:25pm*

**physics**

Procedure 1: Forming Real Images with a Converging Lens a) Obtain the focal length f of the small converging lens by focusing the image of a distant light bulb on the cardboard screen. Mount the lens and the screen on the meter stick. Position the screen at a convenient ...
*Friday, April 17, 2015 at 6:01pm*

**physics**

A 30-caliber rifle with a mass of 2.94 kg fires a 9.73- g bullet with a speed of 666 m/s with respect to the ground. What kinetic energy is released by the explosion of the gunpowder that fires the bullet? (Note there is a tolerance 0.1 percent for the answer
*Friday, April 17, 2015 at 4:00pm*

**physics**

An elastic collision occurs between two air hockey pucks in which one puck is at rest and the other is moving with a speed of 0.7 m/s. After the collision, the puck initially in motion makes an angle of 20.00 o with its original direction, and the struck puck moves at an angle...
*Friday, April 17, 2015 at 3:07pm*

**physics**

The Universe expands according to the Hubble's law: velocity is proportional to distance. There must be some distance, therefore, at which the velocity reaches the speed of light. This defines the horizon. The Doppler shift is so huge that the length of waves becomes ...
*Friday, April 17, 2015 at 2:45pm*

**physics**

An elastic collision occurs between two air hockey pucks in which one puck is at rest and the other is moving with a speed of 0.7 m/s. After the collision, the puck initially in motion makes an angle of 20.00 o with its original direction, and the struck puck moves at an angle...
*Friday, April 17, 2015 at 2:38pm*

**physics**

Answer the following question:Be sure to show all work. Include formulae and units.Be sure to include relavant, meaningful diagram and a complete circuit diagram with circuit related problem. take enough space, don't try to squeeze everything on a small space!(problems are...
*Friday, April 17, 2015 at 2:06pm*

**physics**

A honeybee with a mass of 0.175 g lands on one end of a popsicle stick (Active Example 9-2). After sitting at rest for a moment, the bee runs toward the other end with a velocity 1.75 cm/s relative to the still water. What is the speed of the 5.00 g stick relative to the water...
*Friday, April 17, 2015 at 2:04pm*

**physics**

Two 75.0 kg hockey players skating at 5.60 m/s collide and stick together. If the angle between their initial directions was 115°, what is their velocity after the collision? (Let the motion of player 1 be in the positive x-direction and the motion of player 2 be at an ...
*Friday, April 17, 2015 at 2:03pm*

**physics **

To balance a 29.8 kg automobile tire and wheel, a mechanic must place a 58.2 g lead weight 25.0 cm from the center of the wheel. When the wheel is balanced, its center of mass is exactly at the center of the wheel. How far from the center of the wheel was its center of mass ...
*Friday, April 17, 2015 at 2:01pm*

**physics**

Through beta decay, 55Cr (Chromium‑55 –with mass 54.94080 u) emits an electron (0.00055 u) leaving a daughter nucleus of 55Mn (manganese‑55 with mass 54.93800 u). a) How many different particles to we get out of this reaction b) How much energy in MeV is ...
*Friday, April 17, 2015 at 1:40pm*

**Stream Physics Hydrology - HELP!!!!**

1a) An aqueous solution containing 35 kg of endosuflan insecticide is accidentally released into a small stream. The stream dimensions are 17.5 meters wide and 1.15 meters deep. The stream velocity is 1.1 m/s. The stream channel drops 24m over a distance of 10 km. Endosuflan ...
*Friday, April 17, 2015 at 1:08pm*

**physics**

If a calculated quantity has units of T • m/A, that quantity could be Answer choices a magnetic torque. 1.0. 2.an electric field. 3.an electric potential. 4.a magnetic field.
*Friday, April 17, 2015 at 12:00pm*

**physics**

A charged particle is observed traveling in a circular path of radius R in a uniform magnetic field. If the particle was traveling twice as fast, the radius of the circular path would be 8R. R/4. R/2. 2R. 4R. expanation lso
*Friday, April 17, 2015 at 11:19am*

**physics**

1 The specific heat of a substance at its boiling point or melting point Is 0 Is infinity Is negative lies between 0 and 1 2 A unit mass of solid converted to liquid at its melting point. Heat is required for this process is Specific heat Latent heat of vaporization Latent ...
*Friday, April 17, 2015 at 10:55am*

**Physics**

Proove a*sin(x)+b*sin(x+phi)=((a+b)^2*cos(phi)^1/2*sin(x+phi/2)
*Friday, April 17, 2015 at 10:53am*

**Physics**

Two plane mirrors are positioned at right angles to one another. A ray of light strikes one mirror at an angle of 30° to the normal. It then reflects toward the second mirror. What is the angle of reflection (from the normal) of the light ray OFF the second mirror? I would...
*Friday, April 17, 2015 at 10:45am*

**Physics**

A person whose eyes are 1.50 m above the floor stands in front of a plane mirror. The top of his head is .10 m above his eyes. How far above the floor should the bottom edge of the shortest possible mirror be placed? I know that I need to take half of a number. I just don'...
*Friday, April 17, 2015 at 10:26am*

**physics**

a tennis ball is hit vertically upwards with a velocity of 20m/s. what is it's Decelaration as it moves upward? calculate the maximum height reached by the ball.
*Friday, April 17, 2015 at 8:57am*

**physics**

A 3.6 -kg mass attached to the end of a string swings in a vertical circle (radius = 17.9 m). When the string is horizontal, the speed of the mass is 3.8 m/s. What is the magnitude of the force of the string on the mass at this position?
*Friday, April 17, 2015 at 8:20am*

**physics**

A 1.7 -kg object attached to the end of a string swings in a vertical circle (radius = 80 cm). At the top of the circle the speed of the object is 26.0 m/s. What is the magnitude of the tension in the string at this position?
*Friday, April 17, 2015 at 8:20am*

**physics**

A hawk flies in a horizontal arc of radius 12.0 m at a constant speed of 7.1 m/s. It continues to fly along the same horizontal arc but increases its speed at the rate of 7.9 m/s2. Find the acceleration magnitude under these conditions.
*Friday, April 17, 2015 at 8:20am*

**Physics**

A tiny source emits sound uniformly in all directions. The intensity level ar a dist. Of 2m is 100dB. How much sound power is the soure emitting?
*Friday, April 17, 2015 at 7:18am*

**physics**

A man walks 5.0m due east and then 10.0m N30oE . Find his resultant displacement
*Friday, April 17, 2015 at 4:27am*

**physics**

Calculate the magnitude and direction of the electric force if a charge of −3.5 × 10−7 C is placed in a field of 12 N/C [right].?
*Friday, April 17, 2015 at 1:01am*

**Physics**

I dont know where to even begin... Two equally charged ping pong balls, each having a mass of 5g repel eachother hanging from different strings attached at the same fixed point above. The angle each makes with the vertical is 30 degrees and they are separated by a distance of ...
*Thursday, April 16, 2015 at 11:31pm*

**physics class**

Suppose that you balance a 5 kg ball on the tip of your finger that has an area of 1 cm2. What is the pressure on your finger?
*Thursday, April 16, 2015 at 11:21pm*

**Physics**

A ball rolls off the edge of a 0.75m high lab table with a horizontal speed of 1.50 m/s. Calculate the time that the ball is in flight, calculate the vertical velocity of the ball just before striking the floor, and calculate the horizontal distance(range) that the ball will ...
*Thursday, April 16, 2015 at 8:39pm*

**physics**

A box is suspended by a steel wire via a frictionless pulley The wire has a mass per length of µ = 24.5 × 10 − 3 kg/m. The box is so heavy and the wire so thin that the mass of the wire does not influence the wire tension. The horizontal part of the wire has ...
*Thursday, April 16, 2015 at 6:26pm*

**Physics**

A 1100- kg car collides with a 1400- kg car that was initially at rest at the origin of an x-y coordinate system. After the collision, the lighter car moves at 20.0 km/h in a direction of 25 o with respect to the positive x axis. The heavier car moves at 23 km/h at -50 o with ...
*Thursday, April 16, 2015 at 4:35pm*

**physics**

A bicycle tire is 82 inches across and has a diameter of 26 inches.
*Thursday, April 16, 2015 at 2:59pm*

**physics**

Decide whether each of the following statements are T-True, or F-False. A) Velocity anti-nodes of standing air waves occur at closed ends of tubes. B) Pressure nodes of standing air waves occur at closed ends of tubes. C) Velocity nodes of standing air waves occur at open ends...
*Thursday, April 16, 2015 at 2:48pm*

**College Physics**

Two cars collide at an icy intersection and stick together afterward. The first car has a mass of 1050Kg and was approaching at 8.00m/s due south. The second car has a mass of 700Kg and was approaching at 20.0m/s due west. A) Calculate the final velocity of the cars.(Note ...
*Thursday, April 16, 2015 at 2:07pm*

**physics**

A spaceship has a momentum of 20,000 kg·m/s to the left; its mass is 500 kg. What is the magnitude of its velocity?
*Thursday, April 16, 2015 at 1:56pm*

**statistics**

The distribution of B.A. degrees conferred by a local college is listed below, by major. Major Frequency English 2073 Mathematics 2164 Chemistry 318 Physics 856 Liberal Arts 1358 Business 1676 Engineering 868 9313 What is the probability that a randomly selected degree is not ...
*Thursday, April 16, 2015 at 11:43am*

**physics please help **

A rock of mass 5kg is pushed over the edge of a cliff which is 200m high 1.ignore air resistance and calculate the speed of the rock at the bottom of the cliff. In reality air resistance cannot be ignored. The rock eventually reaches terminal velocity of 30m/s 2.calculate the ...
*Thursday, April 16, 2015 at 10:16am*

**physics**

. A tennis player serves the ball at a height of h with an initial velocity of 40m/s at an angle of 4 0 with the horizontal. Knowing that the ball clears the 0.941m net by 152mm. Determine (a) the height h (b) the distance d from the net to where the ball will land.
*Thursday, April 16, 2015 at 9:55am*

**physics**

A helicopter is flying with a constant horizontal velocity of 144.2 kmph and is directly above the point A when a loose part begins to fall. The part lands 6.5seconds later at point B on an inclined surface. Determine (a) The distance 'd' between points A and B. (b) ...
*Thursday, April 16, 2015 at 9:54am*

**physics**

A ski jumper starts with a horizontal take-off velocity of 25m/s and lands on a straight landing hill inclined at 30 0 . Determine (a) the time between take-off and landin. (b) The length 'd' of the jump. (c) The maximum vertical distance between the jumper and the ...
*Thursday, April 16, 2015 at 9:52am*

**physics**

conducting spherical shells with radiia=10cm and b=30cm are maintained at potentials v(r=b)=0v and v(r=a)=100v.determine v and e in the region between the shells.
*Thursday, April 16, 2015 at 8:17am*

**physics**

The coefficient of apparent expansion of a liquid when determined using two different vessels A and B are gamma1 and gamma2 respectively. If the coefficient of expansion of the vessel A is alpha, the coefficient of linear expansion os the vessel B is a)alphaxgamma1xgamma2/...
*Thursday, April 16, 2015 at 12:36am*

**physics**

A 15-kg block is on a frictionless ramp that is inclined at 20° above the horizontal. It is connected by a very light string over an ideal pulley at the top edge of the ramp to a hanging 19-kg block, as shown in the figure. The string pulls on the 15-kg block parallel to ...
*Wednesday, April 15, 2015 at 10:56pm*

**physics**

A 1000-kg barge is being towed by means of two horizontal cables. One cable is pulling with a force of 80.0 N in a direction 30.0° west of north. In what direction should the second cable pull so that the barge will accelerate northward, if the force exerted by the cable ...
*Wednesday, April 15, 2015 at 10:56pm*

**physics**

A 40-kg box is being pushed along a horizontal smooth surface. The pushing force is 15 N directed at an angle of 15° below the horizontal. What is the magnitude of the acceleration (in m/s2) of the crate?
*Wednesday, April 15, 2015 at 10:55pm*

**physics**

A car of mass 1100 kg that is traveling at 27 m/s starts to slow down and comes to a complete stop in 578 m. What is the magnitude of the braking force (in N) acting on the car?
*Wednesday, April 15, 2015 at 10:55pm*

**physics**

At what altitude should a satellite be placed into circular orbit
*Wednesday, April 15, 2015 at 10:54pm*

**physics**

If I weigh 741 N on Earth at a place where g = 9.80 m/s2 and 5320 N on the surface of another planet, what is the acceleration due to gravity (in m/s2) on that planet?
*Wednesday, April 15, 2015 at 10:54pm*

**Physics**

An engineer has an odd-shaped object of mass 16 kg and needs to find its rotational inertia about an axis through its center of mass. The object is supported on a wire along the desired axis. The wire has a torsion constant κ = 0.4 N· m. If this torsion pendulum ...
*Wednesday, April 15, 2015 at 8:34pm*

**Physics**

If a 0.50-kg block initially at rest on a frictionless, horizontal surface is acted upon by a force of 8.0 N for a distance of 4 m, then what would be the block's velocity?
*Wednesday, April 15, 2015 at 8:27pm*

**Physics**

A bicycler rider is traveling at 7m/s. During an 8s period, the bicycle rider then slows down with acceleration to a speed of 3 m/s. How far does the bicycle rider travel during the 8s? d=7m/s s=3m/s t=8s t x s = d/t x t d = s x t
*Wednesday, April 15, 2015 at 5:35pm*

**Science/Physics **

My question is you walk 3.9 kilometers to school. In gym, you do the 12 minute run and actually make it 2.4 kilometers. After school you walk your friend home first and then go home it is 3.1 kilometers farther than your morning walk to school. What was your total distance ...
*Wednesday, April 15, 2015 at 3:36pm*

**physics**

A skier descends a mountain at an angle of 35.0º to the horizontal. If the mountain is 235 m long, what are the horizontal and vertical components of the skier's displacement?
*Wednesday, April 15, 2015 at 11:31am*

**physics**

When responding to sound, the human eardrum vibrates about its equilibrium position. Suppose an eardrum is vibrating with an amplitude of 6.7 x10-7 m and a maximum speed of 3.9 x10-3 m/s. (a) What is the frequency (in Hz) of the eardrum's vibrations? (b) What is the ...
*Wednesday, April 15, 2015 at 11:14am*

**Physics**

How much energy is require to set a 0.304m phonograph record into rotation at 33.33 revolution per minute if the mass of the record is 0.11kg?
*Wednesday, April 15, 2015 at 10:47am*

**physics**

A boy drops a mango from a tree it falls without rebound wat happens to its momentum
*Wednesday, April 15, 2015 at 7:24am*

**Physics**

8. A 4.70 m long pole is balanced vertically on its tip. What will be the speed (in meters/second) of the tip of the pole just before it hits the ground? (Assume the lower end of the pole does not slip.) I did V^2=0^2+2(9.8)(4.70) and was wrong. I did remember to square root ...
*Wednesday, April 15, 2015 at 5:03am*

**Physics**

8. A 4.70 m long pole is balanced vertically on its tip. What will be the speed (in meters/second) of the tip of the pole just before it hits the ground? (Assume the lower end of the pole does not slip.) I did V^2=0^2+2(9.8)(4.70) and was wrong. I did remember to square root ...
*Wednesday, April 15, 2015 at 4:56am*

**physics**

two identically charged sphere of mass 3 gm each are suspended from a point by threads of length 13 cm. they are separated 10 cm due to repulsion. find the tension of the thread and charge on the sphere?
*Wednesday, April 15, 2015 at 2:40am*

**physics**

find the weight of a person with a mass of 68.0kg
*Wednesday, April 15, 2015 at 1:00am*

**Physics **

We think of the width of the central maxima on our screen as a measure of the uncertainty in the direction of travel of the protons. What happens to this uncertainty in the direction of travel (momentum) as the slit width narrows?
*Wednesday, April 15, 2015 at 12:28am*

**Physics **

When we force protons through a narrow slit, we are gaining certainty in their position. As we gain certainty in their position, what should happen to the certainty on momentum?
*Wednesday, April 15, 2015 at 12:26am*

**Physics**

The density of a solid is 130gcm^-3 at the temperature of 25 degree Centrigate.Find the Density at 150 degree Celcius if the linear expansion of the solid is 2.0*10^(-5)K^-1. I got the answer to be 129.03.
*Tuesday, April 14, 2015 at 9:05pm*

**Physics**

An antiaircraft gun fires at an elevation of 60° at an enemy aircraft at 10,000m above the ground. At what speed must the cannon be shot to hit the plane at that height.
*Tuesday, April 14, 2015 at 8:31pm*

**Physics**

A stone is thrown vertically upward with an initial speed u.if is the acceleration due to gravity,at what time will the stone return to the starting point
*Tuesday, April 14, 2015 at 7:20pm*

**Physics**

A cannon ball is projected so as to attain maximum range. Find the maximum height attained if the initial velocity is u
*Tuesday, April 14, 2015 at 6:42pm*

**PHYsics**

A centrifuge for separation of sugar crystals in molasses must exert a force of 6 N/g. If the filter drum has a radius of 350 mm, determine the required speed in the revolution per minute I tried the following F = 6 = 10^-3*a a = 6000 = ω^2*r
*Tuesday, April 14, 2015 at 12:19pm*

**physics**

How long would it take to bring a 318 kg car moving at 11.2 m/s to a complete stop if a 602.8 N breaking force is applied?
*Tuesday, April 14, 2015 at 11:02am*

**physics**

An ideal gas at 19.8 °C and a pressure of 2.79 x 105 Pa occupies a volume of 3.66 m3. (a) How many moles of gas are present? (b) If the volume is raised to 7.20 m3 and the temperature raised to 28.5 °C, what will be the pressure of the gas? I got a) right with 419.46, ...
*Tuesday, April 14, 2015 at 10:29am*

**Technical Physics**

A boat is sitting in the middle of the lake. What happens to the water level in the lake when a heavy anchor is thrown overboard? Does the water level rise, lower, or stay the same.
*Tuesday, April 14, 2015 at 10:28am*

**Physics**

4 charges Q1=2C, Q2=3C, Q3=3C & Q4=-4C are placed at the vertices of a square of side 10cm. find the force on 5th charge Q5=1C placed at the center of square.
*Tuesday, April 14, 2015 at 9:58am*

**Physics**

The density of a solid is 130gcm^-3 at the temperature of 25 degree Centrigate.Find the Density at 150 degree Celcius if the linear expansion of the solid is 2.0*10^(-5)K^-1. I got the answer to be 129.03.
*Tuesday, April 14, 2015 at 9:30am*

**Physics**

The angle of a rotating shaft turns in t seconds is given by theta= ω+1/2at^2 and it is given that ω=3 rad/s and α=0.6 rad/s to complete θ=4 radians. Determine the time taken to complete θ=4 radians.
*Tuesday, April 14, 2015 at 8:41am*

**physics**

A centrifuge for separation of sugar crystals in molasses must exert a force of 6 N/g. If the filter drum has a radius of 350 mm, determine the required speed in the revolution per minute I tried the following F = 6 = 10^-3*a a = 6000 = ω^2*r
*Tuesday, April 14, 2015 at 8:22am*

**physics**

A ball is thrown vertically upward from the edge of a cliff of height 131 m. The initial velocity is 77.7 m/s. how high is the cliff?
*Tuesday, April 14, 2015 at 8:11am*

**physics**

A centrifuge for separation of sugar crystals in molasses must exert a force of 6 N/g. If the filter drum has a radius of 350 mm, determine the required speed in the revolution per minute I tried the following F = 6 = 10^-3*a a = 6000 = ω^2*r
*Tuesday, April 14, 2015 at 7:01am*

**physics**

a particle covers 1/2 distance between A and B with a velocity V0. during 1/2 of the time required to cover the remaining distance the particle moves with a velocity V1 and rest moves with a velocity V2. find the average velocity of the particle
*Tuesday, April 14, 2015 at 6:04am*

**Physics**

In exercising, a weight lifter loses 0.236 kg of water through evaporation, the heat required to evaporate the water coming from the weight lifter's body. The work done in lifting weights is 1.41 x 105 J. (a) Assuming that the latent heat of vaporization of perspiration is...
*Tuesday, April 14, 2015 at 5:06am*

**Physics**

A train accelerates from the rest at the station A at a rate of 0.8 m/s2 for 25 s, the travels at constant velocity for 77.5 s before it comes to rest at the station B after period of retardation lasting 20 s. What is the distance between stations A and B, and the average ...
*Tuesday, April 14, 2015 at 4:16am*

**physics**

Choose one of the Laws of Thermodynamics (zeroth, first, second, or third) and give a brief summary of its development. Who is credited with "discovering" it and when? How did the four laws come to be ordered as they are? Please explain in detail
*Tuesday, April 14, 2015 at 2:55am*

**physics**

A machine with an efficiency of 100% is said to be efficient. a) If a lever has a distance of 4m from the pivot to where a load of 500N is applied and a distance of 1m from the pivot to where the load is,calculate the efficiency of the lever when height moved by effort i 3m ...
*Tuesday, April 14, 2015 at 2:30am*

**physics**

A 10kilow walts electric motor is used to raise a 400kg load of bricks to a height of 60meters.The efficiency of the motor 80%.what is the input energy?
*Tuesday, April 14, 2015 at 2:13am*

**physics**

A particle starts moving from rest with uniform acceleration.It travels a distance x in first 2 sec and a distance y in the next 2 sec.Then Answer) y=3x
*Tuesday, April 14, 2015 at 12:46am*

**physics**

a body of mass 25kg,moving at 3m/s on a rough horizontal floor is brought to rest after sliding through a distance of 2.5m on the floor. calculate the coefficient of sliding friction [g=10ms-2]
*Tuesday, April 14, 2015 at 12:30am*

**PHYSICS**

Calculate the maximum height the tank shell reaches using the initial speed (18 m/s), half-time(1.8), and angle(75).
*Monday, April 13, 2015 at 11:48pm*

**physics**

Calculate the range of the projectile using the initial speed and angle. Use g = 9.8m/s your calculation. Initial speed is 18m/s Angle is 75 Help please !!
*Monday, April 13, 2015 at 11:14pm*

**Physics**

A soccer ball is kicked from the edge of a cliff with a velocity of 12.0m/s horizontally. If the ball landed 47.9m from the base of the cliff, how tall is the cliff?
*Monday, April 13, 2015 at 7:37pm*

**physics**

A 4.0kg particle collides with a 6.0 kg particle that is at rest at 10m/s. What is the velocity of the particles after the collision
*Monday, April 13, 2015 at 7:27pm*

**physics **

When the lights of an automobile are switched on, an ammeter in series with them reads 9.70 A and a voltmeter connected across them reads 12.20 V. When the electric starting motor is also turned on, the ammeter reading drops to 7.30 A and the lights dim somewhat. If the ...
*Monday, April 13, 2015 at 5:43pm*

**Physics**

I have a question on fluids. Water in a section 1.2m wide, 2m high. retained by sluice gate that can pivot about its base. There is a retaining cable at the top of the gate. Determine tension in the retaining cable at the top of the gate when the depth of water is 1.8m. ...
*Monday, April 13, 2015 at 3:49pm*

**physics **

A flying bat emits squeaks at a frequency of 80 MHz, if a stationary observer picks up the frequency of the squeaks as 78 MHz, is the bat moving towards or away from the listener? Determine the speed of the bat.
*Monday, April 13, 2015 at 12:43pm*

**Physics 2**

Calculate the maximum height using the initial speed, half-time, and angle. The initial speeed is 9.8m/s, half time is 1.8, and the angle is 75.
*Monday, April 13, 2015 at 9:58am*

**Physics**

Calculate the maximum height using the initial speed, half-time, and angle. The initial speeed is 18m/s, half time is 1.8, and the angle is 75
*Monday, April 13, 2015 at 9:52am*

**Physics**

Ann, Sam and you take a trip to the orbiting International Space Station, bringing along a hula hoop that is 1.02 m in diameter (= 2R) and has a mass Mh = 2.0 kg. You are watching from a viewport while Sam and Ann go outside for a (space) walk. You see both Sam and Ann ...
*Monday, April 13, 2015 at 8:25am*

**physics**

A block of mass M1 = 15 kg is lying on a horizontal friction-less surface is connected to a string passing over a friction-less pulley. A mass of M2 = 25 kg is hanging at its other end as shown in the figure below. (i) Find the acceleration in the masses. (ii) What is the ...
*Monday, April 13, 2015 at 7:35am*

**Physics**

A sprinter crosses the finish line of a race. The roar of the crowd in front approaches her at a speed of 357m/s . The roar from the crowd behind her approaches at 341m/s . A) What is the speed of the sound? B) What is the sprinter's speed?
*Sunday, April 12, 2015 at 11:42pm*

**Physics**

You have 250 g of water in an aluminium calorimeter with a mass of 125 g. How long will it take to increase the temperature of the water and calorimeter from 20C to 37C if the system is heated by a resistive heating element with 8 V across the resistor and 0.75 A flowing ...
*Sunday, April 12, 2015 at 11:06pm*

**Physics**

A not so brilliant physics students wants to jump from their 3rd floor apartment window to the swimming pool below. The problem is the base of the apartment is 8.00 meters from the pool’s edge. If the window is 20.0 meters high, how fast does the student have to be ...
*Sunday, April 12, 2015 at 9:20pm*

**Physics**

3. A bullet is fired from at a shooting range. The bullet hits the ground after 0.32 seconds. How far did it travel horizontally and vertically in this time if it was fired at a velocity of 1100 m/s?
*Sunday, April 12, 2015 at 9:19pm*

**PHYSICS math**

2. An airplane is 50,000 m above an observer and 2.1 km to the west of them and 1.5 km to the north of you. Determine the angle to the plane in the x – y axis and the total distance to the plane from you. Choose the x-axis east, y axis north, and z axis up
*Sunday, April 12, 2015 at 9:18pm*