Saturday

May 30, 2015

May 30, 2015

**physics**

The car stationary in front of a red traffic light. As the light turns green , a truck goes past at a constant velocity of 1.5 m/s. At the same moment , the car begins to accelerate at 1.25 m/s 2 . When it reaches 2.5 m/s the car continues at this velocity . When does the car ...
*Friday, October 31, 2014 at 11:36pm*

**physics**

The car stationary in front of a red traffic light. As the light turns green , a truck goes past at a constant velocity of 1.5 m/s. At the same moment , the car begins to accelerate at 1.25 m/s 2 . When it reaches 2.5 m/s the car continues at this velocity . When does the car ...
*Friday, October 31, 2014 at 11:32pm*

**physics**

A rifle fires a 1.27 x 10-2-kg pellet straight upward, because the pellet rests on a compressed spring that is released when the trigger is pulled. The spring has a negligible mass and is compressed by 7.87 x 10-2 m from its unstrained length. The pellet rises to a maximum ...
*Friday, October 31, 2014 at 11:16pm*

**physics**

An explosion occurs at the end of a pier. The sound reaches the other end of the pier by traveling through three media: air, fresh water, and a slender metal handrail. The speeds of sound in air, water, and the handrail are 356, 1460, and 5400 m/s, respectively. The sound ...
*Friday, October 31, 2014 at 10:58pm*

**physics**

A rifle fires a 1.27 x 10-2-kg pellet straight upward, because the pellet rests on a compressed spring that is released when the trigger is pulled. The spring has a negligible mass and is compressed by 7.87 x 10-2 m from its unstrained length. The pellet rises to a maximum ...
*Friday, October 31, 2014 at 10:14pm*

**Physics**

A block of mass m = 3.65 kg is attached to a spring (k = 27.5 N/m) by a rope that hangs over a pulley of mass M = 7.30 kg and radius R = 2.81 cm, as shown in the figure. a) Treating the pulley as a solid homogeneous disk, neglecting friction at the axle of the pulley, and ...
*Friday, October 31, 2014 at 8:08pm*

**Physics**

I would really appreciate the help for this assignment. A small reasoning for the answer would be very helpful. Thank you. A sphere of mass m and radius r is attached to the rim of a disk (mass M, radius R). The disk is rotating counter-clockwise with a constant period T ...
*Friday, October 31, 2014 at 8:02pm*

**physics**

The drawing shows two transverse waves traveling on two strings. The linear density of each string is 0.0483 kg/m, and the tension is provided by a 15.0-N block that is hanging from the string. Determine the speed of the wave in part (a) and part (b) of the drawing.
*Friday, October 31, 2014 at 8:01pm*

**Physics**

Bats are extremely adept at catching insects in midair. If a 62-g bat flying in one direction at 9 m/s catches a 6-g insect flying in the opposite direction at 4 m/s, what is the speed of the bat immediately after catching the insect?
*Friday, October 31, 2014 at 7:20pm*

**Physics**

A skateboarder of mass 38.0 kg is riding her 3.90-kg skateboard at a speed of 5.40 m/s. She jumps backward off her skateboard, sending the skateboard forward at a speed of 8.5 m/s. At what speed is the skateboarder moving when her feet hit the ground?
*Friday, October 31, 2014 at 6:54pm*

**Physics**

Three children are fighting over a toy. One child pulls on the toy with a force of 100N at an angle of 37° north of east. The second child pulls on the toy with a force of 200N south. The third child pulls with a force of 250N at an angle of 20° south of west. Watching...
*Friday, October 31, 2014 at 5:26pm*

**physics**

A 2.0kg book is lying on a 0.74m high table. You pick it up and place it on a bookshelf 2.0m above the floor
*Friday, October 31, 2014 at 4:47pm*

**Physics**

Jeron has a tendency to drop his bowling ball upon release when bowling. Instead of having the ball on the floor at the completion of his swing, Jeron lets go of the ball 0.35m above the floor. If he throws the ball with a horizontal velocity of 5.3m/s, what distance does it ...
*Friday, October 31, 2014 at 4:35pm*

**Physics**

Alexis Farias realizes her dream to play golf on the moon. She hits a golf ball with an initial velocity of 23.5m/s at an angle of 35.0 degrees above the horizontal. The acceleration due to gravity on the moon is 1.67m/s^2. A). How long is the golf ball in the air? B). How far...
*Friday, October 31, 2014 at 4:32pm*

**Physics**

Alexis Farias realizes her dream to play golf on the moon. She hits a golf ball with an initial velocity of 23.5m/s at an angle of 35.0 degrees above the horizontal. The acceleration due to gravity on the moon is 1.67m/s^2. A). How long is the golf ball in the air? B). How far...
*Friday, October 31, 2014 at 4:29pm*

**Physics**

A billiard ball of mass m = 0.250 kg hits the cushion of a billiard table at an angle of θ1 = 58.8° and a speed of v1 = 28.4 m/s. It bounces off at an angle of θ2 = 71.0° and a speed of v2 = 10.0 m/s. (a) What is the magnitude of the change in momentum of the...
*Friday, October 31, 2014 at 3:48pm*

**Physics**

A 1424-kg railroad car traveling at a speed of 11 m/s strikes an identical car at rest. If the cars lock together as a result of the collision, what is their common speed (in m/s) afterward?
*Friday, October 31, 2014 at 3:47pm*

**Physics **

700 kg plane is traveling at 90 m/s at altitude of 1500 m what is planes total mechanical energy
*Friday, October 31, 2014 at 3:21pm*

**Physics**

A satellite orbits a planet at 4000m/s, and the acceleration of gravity (centripetal acceleration) on the satellite is 0.58m/s2. What is the diameter of the orbit of the satellite? (Enter your answer in scientific notation utilizing "e" format and rounding the ...
*Friday, October 31, 2014 at 3:11pm*

**Physics**

A cord 0.65m long exerts a centripetal force of 23N on a whirling 2kg mass tied to the end of the cord. What is the velocity of the whirling mass? Round to nearest tenth. For this problem, I used to formula V = square root of f/rm. I did the square root of 23/0.65(2) = 8.4m/s^...
*Friday, October 31, 2014 at 3:09pm*

**Physics**

An object of mass 2.5 kg has speed of 15 m/s when height is 5m above ground what is speed when 12 m above ground?
*Friday, October 31, 2014 at 3:06pm*

**physics**

A telescope that has a 100 cm focal length objective and a 3.00 cm focal length eyepiece. Find the distance between the objective and eyepiece lenses in the telescope needed to produce a final image very far from the observer, where vision is most relaxed. Note that a ...
*Friday, October 31, 2014 at 3:05pm*

**Physics**

A 3m long weightless beam is supported at each end by cables (a scaffold). A painter weighing 900N stands 1m from the left cable. Calculate the tension (force) in each cable. I really don't understand this question.
*Friday, October 31, 2014 at 3:01pm*

**Physics**

A 700 kg plane is traveling at 90 m/s at an altitude of 1500 m. What is the total mechanical energy?
*Friday, October 31, 2014 at 2:56pm*

**Science Physics**

A flat-bottom river barge is 30.0 ft wide, 85.0 ft long, and 15.0 ft deep. (a) How many ft3 of water will it displace while the top stays 3.00 ft above the water? (b) What load in tons will the barge contain under these conditions if the empty barge weighs 160 tons in dry dock?
*Friday, October 31, 2014 at 12:28pm*

**Physics**

I was given this problem, and are having problems. I am taking AP Physics and I want to be able to understand the concept. Thank you for your help. A block of mass m = 3.65 kg is attached to a spring (k = 27.5 N/m) by a rope that hangs over a pulley of mass M = 7.30 kg and ...
*Friday, October 31, 2014 at 12:26pm*

**Physics**

This is a very confusing problem, I had never taken physics before and it is going to kill my GPA. can someone please help me solve this problem. I have a quiz coming up. Thanks for the help. The flywheel of an old steam engine is a solid homogeneous metal disk of mass M = 137...
*Friday, October 31, 2014 at 12:12pm*

**Physics**

This is very confusing to me, I tried a couple of the problems and got them wrong. I would really appreciate the help, and an explanation to study for the exam. Thank you in advance. You are the technical consultant for an action-adventure film in which a stunt calls for the ...
*Friday, October 31, 2014 at 12:07pm*

**physics**

A skier leaves the starting gate at the top of a ski ramp with an initial speed of 4.00 m/s (Figure 6-41). The starting position is 120 m higher than the end of the ramp, which is 3.00 m above the snow. Find the final speed of the skier if he lands 145 m down the 20.0° ...
*Friday, October 31, 2014 at 10:06am*

**physics**

Assuming you are on Earth, where acceleration due to gravity is 9.81 meters/second2, and you have a pendulum with a cord that is 0.65 meters long, what is the period?
*Friday, October 31, 2014 at 10:02am*

**physics**

HEy guys just wondering. What would be the basic theory to reverse gravity? Explain needed so basically using gravity to push things up? How would you reverse the energy. Any background knowledge?
*Friday, October 31, 2014 at 8:24am*

**physics**

wheel is spinning with angular speed 8.6 radian/sec.small fractional force on shaft causes a constant angular deacceleration and wheel come to rest in 192 sec.what is angular acceleration and total angle turned during the slow down
*Friday, October 31, 2014 at 6:51am*

**physics**

starting from rest grinding stone has constant angular acceleration 20 rad/sec at time = 0.reference axis is AB.what is angular displacement of line AB.
*Friday, October 31, 2014 at 6:47am*

**venn diagram**

venn diagram solving for 3 students likes geography physics science 75 likes only one subject 65 likes exactly two 15 like all three.1)how many students in a class 2)how many students like atleast one 3)how many students like only physics 4)how many students like only ...
*Friday, October 31, 2014 at 3:21am*

**physics**

If the speed of light through material Z is 2.5 × 108 m/s, what is this material’s index of refraction? The speed of light in a vacuum is 3 × 108 m/s.
*Friday, October 31, 2014 at 1:30am*

**physics**

A skier leaves the starting gate at the top of a ski ramp with an initial speed of 4.00 m/s (Figure 6-41). The starting position is 120 m higher than the end of the ramp, which is 3.00 m above the snow. Find the final speed of the skier if he lands 145 m down the 20.0° ...
*Friday, October 31, 2014 at 12:24am*

**Physics**

At an amusement park, a swimmer uses a water slide to enter the main pool. If the swimmer slides without friction, and descends through a vertical height of 3.01 m, and has a initial speed of 0.970 m/s, what is her speed at the bottom of the slide? ??? m/s
*Thursday, October 30, 2014 at 11:16pm*

**Physics**

I'm supposed to to calculate an experimental value for the acceleration of gravity from the slope of an acceleration vs. delta mass graph... also i'm supposed to find the percent error (to the normal acceleration of gravity of 9.8).. the slope is .442 i'm not sure ...
*Thursday, October 30, 2014 at 10:00pm*

**Physics**

A 2110 kg car traveling at 10.7 m/s collides with a 2780 kg car that is initially at rest at the stoplight. The cars stick together and move 2.00 m before friction causes them to stop. Determine the coefficient of kinetic friction betwen the cars and the road, assuming that ...
*Thursday, October 30, 2014 at 9:34pm*

**Physics**

A firefighter with a mass of 52 kg slides down a vertical pole with an acceleration of 3 m/s/s . The acceleration of gravity is 10 m/s/s. What is the friction force that is acting on him
*Thursday, October 30, 2014 at 9:09pm*

**Physics**

A crane is lowering two boxes downward at a constant velocity. The cable from the crane is attached directly to the upper box, m1, which has a mass of 95kg and a second cable hanging from the upper box supports the lower box, m2, which has a mass of 140kg. Determine the ...
*Thursday, October 30, 2014 at 8:22pm*

**Physics**

A 120kg box is sliding down a hill at a constant speed. The angle of the incline is 32 degrees. Determine the normal force of the hill on the box. Determine the amount of friction on the box.
*Thursday, October 30, 2014 at 8:20pm*

**physics**

A 71.5 kg ice skater moving to the right with a velocity of 2.92 m/s throws a 0.16 kg snowball to the right with a velocity of 20.1 m/s relative to the ground.
*Thursday, October 30, 2014 at 8:13pm*

**physics**

Displacement vectors A, B, and C add up to a total of zero. Vector A has a magnitude of 1550 m and a direction of 22.9° north of east. Vector B has a direction of 41.0° east of south, and vector C has a direction of 35.2° north of west. Find the magnitudes of ...
*Thursday, October 30, 2014 at 8:01pm*

**physics**

A traffic light weighting 145 newtons hangs from a vertical cable tied to two other cables that are fastened to a support. The upper cables make angles of 31.0 degrees and 57.0 degrees with the horizontal. Find the tension in each of the three cables.
*Thursday, October 30, 2014 at 7:30pm*

**physics**

Displacement vectors A,B,and C add up to a total of zero. Vector A has a magnitude of 1550 m and a direction of 24.1° north of east. Vector B has a direction of 41.0° east of south, and vector C has a direction of 33.4° north of west. Find the magnitudes of vector ...
*Thursday, October 30, 2014 at 6:22pm*

**physics**

A spy in a speed boat is being chased down a river by government officials in a faster craft. Just as the officials’ boat pulls up next to the spy’s boat, both boats reach the edge of a 5.0 m waterfall. The spy’s speed is 15 m/s and the officials’ speed is ...
*Thursday, October 30, 2014 at 6:08pm*

**physics**

a chair has a mass of 15kg.If a cat sits on the chair, and the cat has a mass of 5.4kg, what is the normal force on the chair?
*Thursday, October 30, 2014 at 6:03pm*

**physics**

Full explanation of transverse wave with sutable example
*Thursday, October 30, 2014 at 5:50pm*

**Physics Math**

A flat-bottom river barge is 30.0 ft wide, 85.0 ft long, and 15.0 ft deep. (a) How many ft3 of water will it displace while the top stays 3.00 ft above the water? (b) What load in tons will the barge contain under these conditions if the empty barge weighs 160 tons in dry dock?
*Thursday, October 30, 2014 at 5:42pm*

**physics**

Bob, who has a mass of 80kg , can throw a 550g rock with a speed of 27m/s . The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.0 m. What constant force must Bob exert on the rock to throw it with this speed? If Bob ...
*Thursday, October 30, 2014 at 5:33pm*

**physics**

an object of mass m is suspended by a string of length 2m .the object is rotated in a horizontal circle show the relationship between the tension and mass and linear velocity of the body when the string make an angle to the horizontal
*Thursday, October 30, 2014 at 4:49pm*

**Physics**

The circuit shown below is in a uniform magnetic field that is into the page and is decreasing in magnitude at the rate of 150 tesla/second. What current does the ammeter read?
*Thursday, October 30, 2014 at 3:50pm*

**Physics**

A set of twins work in the Sears Tower, a very tall office building in Chicago. One works on the top floor and other works in the basement. Considering general relativity, which twin will age more slowly?
*Thursday, October 30, 2014 at 3:49pm*

**Physics**

An experiment is designed in which a proton and an antiproton collide, producing a particle with mass 9700 MeV. What must be the incident kinetic energies and velocities of the colliding particles?
*Thursday, October 30, 2014 at 3:48pm*

**Physics**

Creating Z_0 boson via symmetric beams a. Z0 boson has a rest mass energy of 91.187 GeV. It is produced in collisions of positrons and electrons. e^- + e^+ to Z_0 How much kinetic energy must the positrons and electrons in symmetric colliding beams have to produce the Z0 boson...
*Thursday, October 30, 2014 at 3:48pm*

**Physics**

Creating Z_0 boson via symmetric beams a. Z0 boson has a rest mass energy of 91.187 GeV. It is produced in collisions of positrons and electrons. e^- + e^+ to Z_0 How much kinetic energy must the positrons and electrons in symmetric colliding beams have to produce the Z0 boson...
*Thursday, October 30, 2014 at 3:46pm*

**physics**

A pelican flying along a horizontal path drops a fish from a height of 3.1 m. The fish travels 8.4 m horizontally before it hits the water below. What was the pelican’s initial speed? The acceleration of gravity is 9.81 m/s 2 . Answer in units of m/s
*Thursday, October 30, 2014 at 3:25pm*

**Math/Physics**

The potential at the surface of a sphere (radius R) is given by V_0 = k cos 3theta where k is constant. Find the potential inside and outside the sphere as well as the surface charge density (lower case sigma(theta)) on the sphere. (assume there is no charge inside or outside ...
*Thursday, October 30, 2014 at 3:14pm*

**Math/Physics**

My question is this: The potential at the surface of a sphere (radius R) is given by V_0 = k cos 3theta where k is constant. Find the potential inside and outside the sphere as well as the surface charge density (lower case sigma(theta)) on the sphere. (assume there is no ...
*Thursday, October 30, 2014 at 2:45pm*

**physics**

How do i find the length of a projection of a vecor A=3x+y+2z on the xy plane? and how do i find the unit vecotr in the xy plane that is perpendiculer to vector A?
*Thursday, October 30, 2014 at 2:36pm*

**physics**

Displacement vectors A, B, and C add up to a total of zero. Vector A has a magnitude of 1550 m and a direction of 22.9° north of east. Vector B has a direction of 41.0° east of south, and vector C has a direction of 35.2° north of west. Find the magnitudes of ...
*Thursday, October 30, 2014 at 2:20pm*

**physics**

A car travels in a straight line for 3.9 h at a constant speed of 63 km/h. What is its acceleration? Answer in units of m/s2
*Thursday, October 30, 2014 at 1:17pm*

**physics**

A car traveling at 6.5m/s accelerates 3.6m/s2 to reach a speed of 16.0 m/s. How long does it take for this acceleration to occur? Answer in units of s
*Thursday, October 30, 2014 at 1:17pm*

**physics**

A car moving westward along a straight, level road increases its velocity uniformly from +17 m/s to +40 m/s in 10.7 s. What was the car’s acceleration? Answer in units of m/s2
*Thursday, October 30, 2014 at 1:16pm*

**physics**

A ball initially at rest rolls down a hill with an acceleration of 4.5 m/s2. If it accelerates for 7.9 s, how far will it move? Answer in units of m
*Thursday, October 30, 2014 at 1:16pm*

**physics**

A baby sitter pushing a stroller starts from rest and accelerates uniformly at a rate of 0.557 m/s2. What is the velocity of the stroller after it has traveled 5.85 m? Answer in units of m/s
*Thursday, October 30, 2014 at 1:15pm*

**physics**

A car accelerates from rest at 2.57 m/s2. What is the velocity at the end of 5.4 s? Answer in units of m/s
*Thursday, October 30, 2014 at 1:14pm*

**physics **

A bullet is fired straight up from a gun with a muzzle velocity of 208 m/s. Neglecting air resistance, what will be its displacement after 2.6 s? The acceleration of gravity is 9.8 m/s2 .
*Thursday, October 30, 2014 at 1:11pm*

**physics**

A crate is given an initial speed of 5.0m/s up the 22.5∘ plane shown in (Figure 1) . Assume μk = 0.12.
*Thursday, October 30, 2014 at 12:58pm*

**Physics**

A "seconds pendulum" is one that moves through its equilibrium position once each second. (The period of the pendulum is precisely 2.000 s.) The length of a seconds pendulum is 0.9925 m at Tokyo and 0.9948 m at Cambridge, England. What is the ratio of the free-fall ...
*Thursday, October 30, 2014 at 12:09pm*

**Physics**

The angular position of a pendulum is represented by the equation θ = 0.0340 cos ωt, where θ is in radians and ω = 5.43 rad/s. Determine the period and length of the pendulum. What equations would I use to find the period and the length.
*Thursday, October 30, 2014 at 12:08pm*

**Physics**

A 2110 kg car traveling at 10.7 m/s collides with a 2780 kg car that is initially at rest at the stoplight. The cars stick together and move 2.00 m before friction causes them to stop. Determine the coefficient of kinetic friction betwen the cars and the road, assuming that ...
*Thursday, October 30, 2014 at 8:30am*

**physics**

A ball is rolled up a ramp at 2.50 m/s. The ball slows down for 5.00 s and then rolls back down. Assume frictions isn't a factor and that the up ramp is the positive. At what point does the ball's acceleration change and what is the acceleration on the way down?
*Thursday, October 30, 2014 at 8:13am*

**Physics**

A 3.20 kg mud ball has a perfectly inelastic collision with a second mud ball that is initially at rest. The composite system moves with a speed equal to one-half the original speed of the 3.20 mud ball. What is the mass of the second mud ball? kg
*Thursday, October 30, 2014 at 8:02am*

**physics**

A block of wood with mass M = 0.440kg hangs at rest (Vi=0) from the ceiling by a string and a m = 0.0720kg elastic ball is thrown straight upward striking the bottom of the block with a speed of vi=5.74m/s. The ball rebounds from the block in a perfectly elastic collision. How...
*Thursday, October 30, 2014 at 4:19am*

**Physics**

To move a large crate across a rough floor, you push on it with a force (F) at an angle of 21 degrees below the horizontal. Find the force necessary to start the crate moving, given the mass of the crate is 32 kg and the coefficient of static friction between the crate and the...
*Thursday, October 30, 2014 at 2:38am*

**Physics**

A 0.50 kg hammer is taken on a space mission. What is its weight on a planet where the acceleration due to gravity is 3.8 m/s2? 0.50 kg 1.9 kg 0.50 N 1.9 N
*Thursday, October 30, 2014 at 12:26am*

**Physics**

An ideal spring has a spring constant k = 20 N/m. The spring is suspended vertically. A 0.7-kg body is attached to the unstretched spring and released. It then performs oscillations.
*Wednesday, October 29, 2014 at 10:30pm*

**Physics**

A proton that has a mass m and is moving at 250 m/s in the + direction undergoes a head-on elastic collision with a stationary carbon nucleus of mass 12m. Find the velocities of the proton and the carbon nucleus after the collision. vp = m/s vcarbon = m/s
*Wednesday, October 29, 2014 at 10:24pm*

**AP physics **

A NFL punter kicks a ball and lands 52 m away and is in the air for 4.8s. Assume that the ball lands at the same level that is is kicked. a. determine the initial velocity of the punt (magnitude and direction) b. determine the maximum height of he punt c. if the punter kicked ...
*Wednesday, October 29, 2014 at 9:59pm*

**Physics**

A 1400 kg car moving south at 10.0 m/s collides with a 2350 kg car moving north. The cars stick together and move as a unit after the collision at a velocity of 5.36 m/s to the north. Find the velocity of the 2350 kg car before the collision. m/s to the south
*Wednesday, October 29, 2014 at 9:44pm*

**AP Physics **

A drag racer starts from rest and accelerates uniformly for 5s covering a distance of 120 m. a. what is the car's acceleration? I did DI=vit+1/2at^2 120=0(5)+(.5)(5^2)a 120/12.5=12.5a/12.5 a= 9.6 m/s^2 b. what is the car's final velocity at the end of the 5s? I did vf=...
*Wednesday, October 29, 2014 at 9:44pm*

**physics**

If 250 joules of work are performed by an engine using 600 joules of energy in 5 seconds, what is the efficiency of the engine?
*Wednesday, October 29, 2014 at 9:34pm*

**Physics**

A 3.5 g dart is fired into a block of wood with a mass of 22.8 g. The wood block is initially at rest on a 1.3 m tall post. After the collision, the wood block and dart land 2.6 m from the base of the post. Find the initial speed of the dart. m/s
*Wednesday, October 29, 2014 at 9:30pm*

**physics**

f Beth exerts a force of 157 . 9 N on the rope, what is the magnitude of the upward component of the force acting on the stake? Answer in units of N
*Wednesday, October 29, 2014 at 8:23pm*

**Fluid Mechanics Physics**

A flat-bottom river barge is 30.0 ft wide, 85.0 ft long, and 15.0 ft deep. (a) How many ft3 of water will it displace while the top stays 3.00 ft above the water? (b) What load in tons will the barge contain under these conditions if the empty barge weighs 160 tons in dry dock?
*Wednesday, October 29, 2014 at 7:32pm*

**Hydraulic Physics**

In a hydraulic system a 20.0-N force is applied to the small piston with cross sectional area 25.0 cm2. What weight can be lifted by the large piston with cross sectional area 50.0 cm2? Would I need to divide both pistons areas then mutiply the force? and or have gravity in ...
*Wednesday, October 29, 2014 at 6:02pm*

**Physics**

A volleyball is launched straight up at an initial velocity of 2.3 m/s. It is then spiked by a taller player 0.8 meters above the launch height. How high did it rise, and how long did the volleyball remain in the air between the players?
*Wednesday, October 29, 2014 at 5:25pm*

**Physics**

A 5.5 kg object with a speed of 4.0 m/s collides head-on with a 13 kg object moving toward it with a speed of 3.0 m/s. The 13 kg object stops dead after the collision. (a) What is the final speed of the 5.5 kg object? m/s (b) Is the collision elastic? Yes No
*Wednesday, October 29, 2014 at 5:06pm*

**PHYSICS**

Why does air pressure decrease with increasing altitude? (SELECT ALL THAT APPLY) The weight of the air above is smaller The weight of the air below is smaller Less air above pushes down There is more air below to push up more strongly Cold air is less dense Hot air rises
*Wednesday, October 29, 2014 at 4:00pm*

**PHYSICS**

Calculate the pressure on the top lid of a chest buried under 4.30 meters of mud with density 1.75X 10^3 kg/m^3 at the bottom of a 12.5 m deep lake
*Wednesday, October 29, 2014 at 3:57pm*

**physics**

A man tosses a 50.0 g ball straight upward from the ground at 25m/s. at the same time a friend drops a 50.0g ball from a 20.0m tree. how long will it take each ball to hit the ground, how high will the balls rise, how much energy is possessed in each ball. at what height will ...
*Wednesday, October 29, 2014 at 3:09pm*

**Physics**

A 0.250-kg ice puck, moving east with a speed of 5.26m/s , has a head-on collision with a 0.990-kg puck initially at rest. Assume that the collision is perfectly elastic.What is the speed of the 0.250-kg puck after the collision?
*Wednesday, October 29, 2014 at 3:07pm*

**Physics**

A 3.20 kg mud ball has a perfectly inelastic collision with a second mud ball that is initially at rest. The composite system moves with a speed equal to one-half the original speed of the 3.20 mud ball. What is the mass of the second mud ball? kg
*Wednesday, October 29, 2014 at 12:52pm*

**Physics**

A 5.3 g coin sliding to the right at 26.8 cm/s makes an elastic head-on collision with a 15.9 g coin that is initially at rest. After the collision, the 5.3 g coin moves to the left at 13.4 cm/s. (a) Find the final velocity of the other coin. cm/s (b) Find the amount of ...
*Wednesday, October 29, 2014 at 12:41pm*

**Physics**

A 4.500 kg block of wood rests on a steel desk. The coefficient of static friction between the block and the desk is μs = 0.455 and the coefficient of kinetic friction is μk = 0.155. At time t = 0, a force F = 12.4 N is applied horizontally to the block. State the ...
*Wednesday, October 29, 2014 at 10:06am*

**Physics**

20 g ball of clay traveling east at 3.0 m/s collides with a 30 g ball of clay traveling north at 2.0 m/s. What are the speed and the direction of the resulting 50 g ball of clay?
*Wednesday, October 29, 2014 at 3:04am*

**physics**

Object A with mass 6.7 kg is moving at 5.1 m/s. Object B with mass 7.4 kg is moving at 4.7 m/s. Object B impacts Object A, and they stick together. With what velocity do the objects move?
*Wednesday, October 29, 2014 at 2:40am*

**Physics**

A 3.0-kg brick rests on a perfectly smooth ramp inclined at 34° above the horizontal. The brick is kept from sliding down the plane by an ideal spring that is aligned with the surface and attached to a wall above the brick. The spring has a spring constant (force constant...
*Wednesday, October 29, 2014 at 2:06am*