Tuesday

February 9, 2016
Number of results: 23,545

**physics**

Imagine a frictionless perfectly straight tunnel which runs from Boston (USA) to Delhi (India). We release (at zero speed) an object in the tunnel in Boston. Assume that the Earth is a perfect sphere with radius 6.4*10^3 km, with a mass of 6.0*10^24 kg and that the mass ...
*October 27, 2013 by anonymous*

**physics**

Imagine a frictionless perfectly straight tunnel which runs from Boston (USA) to Delhi (India). We release (at zero speed) an object in the tunnel in Boston. Assume that the Earth is a perfect sphere with radius 6.4*10^3 km, with a mass of 6.0*10^24 kg and that the mass ...
*October 30, 2013 by ASD*

**Physics**

A ball of mass 522 g starts at rest and slides down a frictionless track, as shown below. It leaves the track horizontally, striking the ground a distance x = 0.81 m from the end of the track after falling a vertical distance h2 = 1.03 m from the end of the track. (a) At what...
*October 14, 2012 by Angela*

**physics**

A stunt pilot in an air show performs a loop-the-loop in a vertical circle of radius 2.97 103 m. During this performance the pilot whose weight is 835 N, maintains a constant speed of 2.25 102 m/s. (a) When the pilot is at the highest point of the loop determine his apparent ...
*December 2, 2012 by HALP!!!*

**Physics **

Problem 3- A 10-g metal ball is moving to the left with a velocity of magnitude 0.4 m/s has a head-on, elastic collision with a larger 30-g metal ball moving to the right with a velocity of magnitude 0.2 m/s. a) Find the speed of the two balls after the collision. b) If the ...
*January 12, 2014 by Mariam*

**Physics**

A stunt pilot in an air show performs a loop-the-loop in a vertical circle of radius 3.70 103 m. During this performance the pilot whose weight is 740 N, maintains a constant speed of 2.25 102 m/s. (a) When the pilot is at the highest point of the loop determine his apparent ...
*February 3, 2016 by Bust Nuttington*

**physics**

A passenger on a moving train tosses a coin with an initial velocity of (-2.25 m/s) + 4.68 m/s) (from the point of view of the passenger). The train's velocity relative to the ground is (11.5 m/s). (a) What is the minimum speed of the coin relative to the ground during its ...
*September 16, 2012 by maria*

**physics**

An airplane maintains a speed of 597 km/h relative to the air it is flying through as it makes a trip to a city 759 km away to the north. (a) What time interval is required for the trip if the plane flies through a headwind blowing at 36.0 km/h toward the south? 1 h (b) What ...
*October 5, 2011 by jon*

**algebra1**

a cyclist completes a 150-mile race in a certain amount of time.she completes another 150-mile race a month later,but this time it takes an hour longer to cover the same distance and her average speed is 5 mph less than in the first race.find the average speed for the cyclist...
*April 27, 2013 by math lover*

**algebra**

An executive drove from home at an average speed of 45 mph to an airport where a helicopter was waiting. The executive boarded the helicopter and flew to the corporate offices at an average speed of 120 mph. The entire distance was 250 miles; the entire trip took three hours. ...
*September 9, 2015 by Aaron*

**math**

An executive drove from home at an average speed of 45 mph to an airport where a helicopter was waiting. The executive boarded the helicopter and flew to the corporate offices at an average speed of 120 mph. The entire distance was 250 miles; the entire trip took three hours. ...
*September 9, 2015 by Matt*

**algebra**

An executive drove from home at an average speed of 45 mph to an airport where a helicopter was waiting. The executive boarded the helicopter and flew to the corporate offices at an average speed of 120 mph. The entire distance was 250 miles; the entire trip took three hours. ...
*September 9, 2015 by Samantha*

**Physics**

A coefficient of kinetic friction, k , is needed to stop a car in a distance D on dry pavement with the wheels locked if the car starts from speed V_0. What coefficient of kinetic friction (in terms of k ) is needed to stop this car in the same distance if it starts from an ...
*February 19, 2008 by Jose*

**physics**

The volume flow rate in an artery supplying the brain is 3.10 10-6 m3/s. (a) If the radius of the artery is 4.50 10-3 m, determine the average blood speed. 1 m/s (b) Find the average blood speed at a constriction in the artery if the constriction reduces the radius by a factor...
*December 12, 2010 by sarah*

**physics**

A spinning disk of mass 5.0 kg and radius 0.25m is rotating about an axis through its center at 400 rev/min. a.) What is the angular velocity of the disk in rad/s? b.) What is the moment of inertia of the disk? c.) If it accelerates at a constant rate to 800 rev/min in 8 sec, ...
*July 29, 2012 by Lauren*

**Physics**

A spinning disk of mass 5.0 kg and radius 0.25m is rotating about an axis through its center at 400 rev/min. a.) What is the angular velocity of the disk in rad/s? b.) What is the moment of inertia of the disk? c.) If it accelerates at a constant rate to 800 rev/min in 8 sec, ...
*July 29, 2012 by Lauren*

**physics**

The two gears, with radii indicated below, have equal teeth spacing and are well-meshed. In all cases, the large gear is turning at the same, constant angular speed. Rlarge Rsmall A 0.4 m 0.2 m B 0.4 m 0.3 m C 0.8 m 0.4 m D 0.6 m 0.5 m E 0.2 m 0.1 m F 0.6 m 0.2 m a. Rank the ...
*April 28, 2011 by steve*

**physics**

In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the second ball had a speed of 2 m/s. a)What is ...
*March 4, 2007 by Chris*

**Math**

A short airplane trip between two cities took 30 minutes when traveling with the wind. The return trip took 45 minutes when traveling against the wind. If the speed of the plane with no wind is 320 mph, find the speed of the wind and the distance between the two cities (hint: ...
*December 7, 2015 by Help Please!*

**algebra**

A student runs 100 meters in 11 seconds. What is the speed of the student? speed = distance over time; 1 mile = 1609 meters 9.1 miles per hour 16 miles per hour 20.3 miles per hour 24 miles per hour pls help
*September 2, 2015 by oscar*

**Physics 20**

A 2.50-kg Pendulum is attatched to a string 11.4m stringis pulled aside until it is.386m above its lowest position and released. The pendulum is designed to emit sound waves at a frequency of 440 Hz; However, as it swings toward and away from an observer, the frequency appears...
*July 13, 2009 by Moe*

**last physics problem!**

A ball of mass 522 g starts at rest and slides down a frictionless track, as shown below. It leaves the track horizontally, striking the ground a distance x = 0.93 m from the end of the track after falling a vertical distance h2 = 1.18 m from the end of the track. (a) At what ...
*April 15, 2010 by brittany*

**physics**

Calculate the ratio of the drag force on a passenger jet flying with a speed of 850 km/h at an altitude of 10 km to the drag force on a prop-driven transport flying at three-fifths the speed and half the altitude of the jet. At 10 km the density of air is 0.38 kg/m3 and at 5.0...
*July 14, 2010 by Sam*

**Physics**

A gull is flying horizontally 8.17 m above the ground at 6.35 m/s. The bird is carrying a clam in its beak and plans to crack the clamshell by dropping it on some rocks below. Ignoring air resistance, what is the horizontal distance to the rocks at the moment that the gull ...
*September 20, 2012 by Josh*

**Physics**

A gull is flying horizontally 8.17 m above the ground at 6.35 m/s. The bird is carrying a clam in its beak and plans to crack the clamshell by dropping it on some rocks below. Ignoring air resistance, what is the horizontal distance to the rocks at the moment that the gull ...
*September 22, 2012 by Kasey*

**Physics**

A gull is flying horizontally 8.17 m above the ground at 6.35 m/s. The bird is carrying a clam in its beak and plans to crack the clamshell by dropping it on some rocks below. Ignoring air resistance, what is the horizontal distance to the rocks at the moment that the gull ...
*September 23, 2012 by Liz*

**physics**

Three identical balls are thrown from a cliff of height, h, above a horizontal plane. One ball is thrown at an angle of 45 degrees above the horizon, the second is thrown horizontally, and the third is thrown at an angle of 30 degrees below the horizon (so, part of this ...
*December 2, 2009 by William*

**physics**

Three identical balls are thrown from a cliff of height, h, above a horizontal plane. One ball is thrown at an angle of 45 degrees above the horizon, the second is thrown horizontally, and the third is thrown at an angle of 30 degrees below the horizon (so, part of this ...
*December 11, 2009 by Kelly*

**math**

A man is walking at an average speed of 4 miles per hour alongside a railroad track. A freight train, going in the same direction at an average speed of 30 miles per hour, requires 5 seconds to pass the man. How long is the freight train? Give your answer in feet. What would ...
*October 5, 2010 by Amy*

**Physics**

Can someone help me find Delta Time for the first 150 meters of this question. Everytime I try and get it by using the quadratic formula I get two negative numbers which I don't think is right. A model rocket is launched straight upward with an initial speed of 50.0m/s. It ...
*September 28, 2007 by Dustin*

**Physics**

A blue car with mass mc = 410.0 kg is moving east with a speed of vc = 23.0 m/s and collides with a purple truck with mass mt = 1248.0 kg that is moving south with a speed of vt = 10.0 m/s . The two collide and lock together after the collision. 1)What is the magnitude of the ...
*October 8, 2012 by Mike*

**Physics**

Transformers are used to increase the voltage produced at power plants. Why is it desirable for the power to be transmitted at high voltage? (a) the the transformer induction will be less resulting in less joule heating (b) then the resistance of the wires will be less ...
*November 4, 2011 by Arielle*

**physics**

A rifle is aimed horizontally at a target 30 m away. The bullet hits teh target 1.9 cm below the aiming point. What are the a) teh bullet's time of flight and b) its speed as it emerges from the rifle? A) is expose to be 62ms B) is expose to be 480m/s this is from by book. But...
*October 24, 2006 by jenny*

**physics**

A block of mass m1 = 2.4 kg initially moving to the right with a speed of 3.3 m/s on a frictionless, horizontal track collides with a spring attached to a second block of mass m2 = 4.1 kg initially moving to the left with a speed of 1.5 m/s as shown in figure (a). The spring ...
*October 14, 2013 by Leticia*

**science check my answers? **

A car travels around a circular turn of radius 50 meters while maintaining a constant speed of 15 m/s. Find the minimum value for the coefficient of friction necessary to keep the car on the road. I got .40 for the minimum value of friction. In icy conditions, the coefficient ...
*January 11, 2014 by Ryan*

**Physics**

A seagull can fly with a speed of 12.5 m/s (relative to the air). (a) How long will it take the gull to fly from his perch 420. m east to the carcass of a dead fish floating in the water if the wind is from the east at a speed of 2.70 m/s? (b) Having eaten lunch (nicely aged, ...
*May 29, 2014 by Kat*

**Physics waves**

in which sprind do transverse waves travel faster, small diameter spring or slinky? i think this be the transverse waves but i not know how to explain why. in which spring do longitudinal waves travel faster? i think that be the small spring because it smaller? do amplitude of...
*January 8, 2012 by Shreya*

**physics**

Driving along a crowded freeway, you notice that it takes a time t to go from one mile marker to the next. When you increase your speed by 4.0 mi/h, the time to go one mile decreases by 11 s. What was your original speed? I used the equation V=d/t; I rearranged it to V=(1/t-11...
*May 13, 2007 by micole*

**physics**

A uranium nucleus 238U may stay in one piece for billions of years, but sooner or later it decays into an a particle of mass 6.64×10−27 kg and 234Th nucleus of mass 3.88 × 10−25 kg, and the decay process itself is extremely fast(it takes about 10−20 s). ...
*January 16, 2010 by Anonymous*

**physics**

A tennis ball is a hollow sphere with a thin wall. It is set rolling without slipping at 4.24 m/s on a horizontal section of a track. It rolls around the inside of a vertical circular loop 90.0 cm in diameter and finally leaves the track at a point 19.0 cm below the horizontal...
*March 2, 2010 by emath*

**College physics**

A 0.006 00-kg bullet traveling horizontally with a speed of 1.00 x 10^3 m/s enters an 20.1-kg door, imbedding itself 10.9 cm from the side opposite the hinges as in the figure below. The 1.00-m wide door is free to swing on its frictionless hinges. At what angular speed does ...
*April 11, 2012 by johnny*

**physics**

A uranium nucleus 238U may stay in one piece for billions of years, but sooner or later it de- cays into an particle of mass 6.64×10−27 kg and 234Th nucleus of mass 3.88 × 10−25 kg, and the decay process itself is extremely fast (it takes about 10−20 s). ...
*April 29, 2012 by kate*

**Physics**

Starting with an initial speed of 5.00 m/s at a height of 0.335 m, a 1.75-kg ball swings downward and strikes a 4.40-kg ball that is at rest, as the drawing shows. (a) Using the principle of conservation of mechanical energy, find the speed of the 1.75-kg ball just before ...
*March 23, 2014 by Bo*

**Physics MCAT, Help please**

A box of mass m = 6kg slides with speed v = 4 m/s across a frictionless floor. It suddenly explodes into two pieces. One piece, with mass m1 = 2kg moves in the same direction with speed v1 = 8m/s. Find the velocity of the second piece. Its answer is 2 m/s , but I dont know how...
*September 24, 2014 by Shahab Mirza*

**Physics**

A catapult on a cliff launches a large round rock towards a ship on the ocean below. The rock leaves the catapult from a height H of 32.0 m above sea level, directed at an angle θ above the horizontal with an unknown speed v0. The projectile remains in flight for 6.00 ...
*December 2, 2014 by Anonymous*

**Physics**

A small rocket is fired in a test range. It rises high into the air and soon runs out of fuel. On the way down it passes near an observer (sitting in a 22.5-m-high tower) who sees the rocket traveling at a speed of 37.9 m/s and moving in a vertical plane at an angle of 50.8° ...
*January 28, 2014 by Anonymous*

**Math**

The formula s = the square root of 18d can be used to fnd the speed s of a car in miles per hour when the car needs d feet to come to a complete stop after slamming on the brakes. If it took a car 12 feet to come to a complete stop after slamming on the brakes, estimate the ...
*September 27, 2012 by Jordan*

**Algebra**

A plane takes off from an airport and flies east at a speed of 350 mph. Ten minutes later, a second plane takes off from the same airport and flies east at a higher altitude at a speed of 400 mph. How long does it take the the second plane to overtake the first plane?
*September 7, 2015 by Doug*

**Science**

Jana looked at her wristwatch as her family drove from syracuse to albany. After fifteen minutes, she checked the odometer on the dashboard to see how many miles they have traveled.What was she measuring? A-Speed B-Motion C-Velocity D-friction Heres what I can't figure out, it...
*April 10, 2009 by Jake*

**Classical Mechanics Physics**

A spherical non-rotating planet (with no atmosphere) has mass m1= 3 ×1024 kg and radius r1= 8000 km. A projectile of mass m2≪m1 is fired from the surface of the planet at a point A with a speed vA at an angle α=30∘ with respect to the radial direction. In its ...
*December 6, 2013 by Anonymous*

**Physics Classical Mechanics**

A spherical non-rotating planet (with no atmosphere) has mass m1= 4 ×1024 kg and radius r1= 5000 km. A projectile of mass m2≪m1 is fired from the surface of the planet at a point A with a speed vA at an angle α=30∘ with respect to the radial direction. In its ...
*December 8, 2013 by Mary*

**Physical Science**

1.Instantaneous speed is measured B. when the object reaches its destination. C. at a particular instant. D. over the duration of the trip. 2. A ball is rolled uphill a distance of 5 meters before it slows, stops, and begins to roll back. The ball rolls downhill 9 meters ...
*June 4, 2013 by Lanny*

**Physics**

1. A car is traveling at 85km/h, find the following: A) Its speed in m/s u = 85km/h = 85km/h * 1000m/km/ 60s/min * 60min/m/h = 85000/ 3600 = 23.61 ANS = 23.61m/s B) How many meters will it travel in 8 seconds = 23.61m/s * 8s ANS = 188.88m C) How long (in seconds) will it take ...
*June 5, 2013 by DANNY*

**Math**

Mark and Sandy are participating in a Bike-a-Thon for charity. Mark oversleeps, so Sandy gets a one hour head start and bikes at a speed of 12 miles per hour. To catch up to Sandy, Mark decides that he needs to bike at a speed of 15 miles per hour. 3.An expression that ...
*November 12, 2013 by Jerald*

**PHYSICS**

1....How much force needed to bring a 3200 lb car from rest to a velocity of 44 m/s in 8 sec.? 2....A ball with a mass of 2 kg move to the right with a speed of 2 m/s. It hits a ball of mass 0.50 kg which is at rest. After collision the second ball moves to the right with a ...
*February 18, 2011 by EM*

**physics**

A red ball is thrown down with an initial speed of 1.2 m/s from a height of 25.0 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 22.9 m/s, from a height of 0.8 meters above the ground. The force of ...
*September 3, 2012 by ali*

**Physics**

A red ball is thrown down with an initial speed of 1.3 m/s from a height of 28.0 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 24.7 m/s, from a height of 0.8 meters above the ground. The force of ...
*January 26, 2013 by Funnyguy*

**Physics**

Waves of all wavelengths travel at the same speed v on a given string. Traveling wave velocity and wavelength are related by v=lambda*f,where v is the wave speed, lambda is the wavelength (in meters), and f is the frequency [in hertz]. Since only certain wavelengths fit ...
*April 13, 2011 by ECU*

**Physics please help**

The gun, mount, and train car of a railway had a total mass of 1.22 x 10^6 kg. The gun fired a projectile that was 80 cm in diameter and weighed 7502 kg. In the firing, the gun has been elevated 20 degrees above the horizontal. If the railway gun at rest before firing and ...
*January 19, 2016 by Khalid*

**phy**

A ball of mass 0.540 kg moving east (+x direction) with a speed of 3.30 m/s collides head-on with a 0.740 kg ball at rest. If the collision is perfectly elastic, what will be the speed and direction of each ball after the collision? a)ball originally at rest m/s b)ball ...
*October 7, 2010 by ami*

**physics**

A blue ball is thrown upward with an initial speed of 22.8 m/s, from a height of 0.8 meters above the ground. 2.8 seconds after the blue ball is thrown, a red ball is thrown down with an initial speed of 10.9 m/s from a height of 29.3 meters above the ground. The force of ...
*September 8, 2014 by jerry*

**Physics**

A billiard ball of mass m = 0.250 kg hits the cushion of a billiard table at an angle of θ1 = 63.4° at a speed of v1 = 24.8 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 billiard...
*October 7, 2010 by Alex*

**Psysik**

From the top of a tower is an object of mass 25 kg lowered at constant speed, 4 m / s with a rope to the ground. After 10 seconds of the rope breaks, and the object falls freely. From the moment (the rope breaks) there is 12 seconds to those standing on top of the tower and ...
*October 18, 2010 by OddbjÃ¸tn*

**physics**

A skater spinning with angular speed of 1.5 rad/s draws in her outstretched arms thereby reducing her moment of inertia by a factor a 3. a) Find her final angular speed. b)What is the ratio of her final angular momentum to her initial angular momentum? c) Determine the ratio ...
*December 2, 2010 by Kevin*

**Physics**

A Texas cockroach of mass 0.17 kg runs counterclockwise around the rim of a lazy Susan (a circular disk mounted on a vertical axle) that has radius 15 cm, rotational inertia 5.5 10-3 kg·m2, and frictionless bearings. The cockroach's speed (relative to the ground) is 2.0 m/s, ...
*October 26, 2009 by Ray*

**Physics**

Water drives a waterwheel (or turbine) of radius 3.0m. The water enters at a speed of v1 = 7.0 m/s and leaves at a speed of v2= 3.0 m/s. A) if 150kg of water passes through per second, what is the rate at which the water delivers angular momentum to the waterwheel? [answer: ...
*April 13, 2008 by Odd*

**Physics**

a 61 kg skier on level snow coasts 184 m to stop from a speed on 12.0 m/s. A) use the work energy principle to find the coefficient of kinetic friction between the skis and the snow. B) suppose a 75 kg skier with twice the starting speed coasted the same distance before ...
*June 18, 2009 by Sarah*

**Physics**

A student throws a water balloon vertically downward from the top of a building. The balloon leaves the thrower's hand with a speed of 6.00 m/s. Air resistance may be ignored, so the water balloon is in free fall after it leaves the thrower's hand. (a) What is its speed after ...
*October 12, 2010 by Anonymous*

**physics**

A 1.5-kg object moves up the y-axis at a constant speed. When it reaches the origin, the forces F1 = 5.0 N at 37 degrees. above the +xaxis, F2 N in the +X direction, F3 = 3.5 N at 45 degrees below the -X axis, and the F4 = 1.5 N in the - y direction are applied to it. a)Will ...
*January 18, 2008 by Will*

**calculus**

The data entry speed (in entries per minute) of a data clerk trainee is represented by the following equation, where x is the number of hours of training he has had. S = 10 0.8x + 4 , 0 ≤ x ≤ 100 What is the rate at which his speed is changing and what does this ...
*March 10, 2011 by Adam Janky *

**physics **

Curve A is banked at 11.2 °, and curve B is banked at an angle of 15.2 °. A car can travel around curve A without relying on friction at a speed of 14.5 m/s. At what speed can this car travel around curve B without relying on friction? Do I need to find radius in order to ...
*October 20, 2014 by S*

**physics**

A venturi meter is a device for measuring the speed of a fluid within a pipe. The drawing shows a gas flowing at a speed v2 through a horizontal section of pipe whose cross-sectional area A2 = 0.0600 m2. The gas has a density of ñ = 1.30 kg/m3. The Venturi meter has a cross-...
*December 4, 2010 by student*

**physics**

A venturi meter is a device for measuring the speed of a fluid within a pipe. The drawing shows a gas flowing at a speed v2 through a horizontal section of pipe whose cross-sectional area A2 = 0.0900 m2. The gas has a density of ñ = 1.50 kg/m3. The Venturi meter has a cross-...
*December 6, 2010 by johnny*

**Physics**

Which of the following involves a non-zero net force? I. A hockey-puck sliding at a constant speed on ice. II. The earth revolving around the sun at a constant speed. III. An object falling near the surface of the earth. A) I only B) III only C) Both I and II D) Both II and ...
*October 13, 2011 by Astrogirl*

**Physics**

Wheel A of radius ra = 13.9 cm is coupled by belt B to wheel C of radius rc = 34.3 cm. Wheel A increases its angular speed from rest at time t = 0 s at a uniform rate of 5.7 rad/s2. At what time will wheel C reach a rotational speed of 168.2 rev/min, assuming the belt does not...
*February 10, 2012 by Marc*

**physics**

The largest railway gun ever built was called Gustav and was used briefly in World War II. The gun, mount, and train car had a total mass of 1.22 106 kg. The gun fired a projectile that was 80.0 cm in diameter and weighed 7502 kg. In the firing illustrated in the figure, the ...
*February 25, 2011 by Anonymous*

**physics**

A hot air balloon is ascending straight up at a constant speed of 6.50 m/s. When the balloon is 13.0 m above the ground, a gun fires a pellet straight up from ground level with an initial speed of 34.0 m/s. Along the paths of the balloon and the pellet, there are two places ...
*September 10, 2013 by eric*

**physics Waves**

in which spring do transverse waves travel faster, small diameter spring or slinky? i think this be the transverse waves but i not know how to explain why. in which spring do longitudinal waves travel faster? i think that be the small spring because it smaller? do amplitude of...
*January 9, 2012 by Shreya*

**physics**

Mario, a hockey player, is skating due south at a speed of 7.05 m/s relative to the ice. A teammate passes the puck to him. The puck has a speed of 9.69 m/s and is moving in a direction of 16.2 ° west of south, relative to the ice. What are (a) the magnitude and (b) direction...
*October 1, 2008 by DK*

**Physics**

Mario, a hockey player, is skating due south at a speed of 6.6 m/s relative to the ice. A teammate passes the puck to him. The puck has a speed of 12.9 m/s and is moving in a direction of 23° west of south, relative to the ice. What are the magnitude and direction (relative to...
*October 9, 2013 by Mario*

**physics**

Mario, a hockey player, is skating due south at a speed of 5.4 m/s relative to the ice. A teammate passes the puck to him. The puck has a speed of 10.0 m/s and is moving in a direction of 27° west of south, relative to the ice. What are the magnitude and direction (relative to...
*October 13, 2013 by butcha*

**Physics**

1) A jetliner, traveling northward, is landing with a speed of 69.3 m/s. Once the jet touches down, it has 787 m of runway in which to reduce its speed to 13.6 m/s. Compute the average acceleration (magnitude and direction) of the plane during landing (take the direction of ...
*May 27, 2012 by Hannah*

**Science - Please Check my Answer 2**

My problem: One runner in a relay race has a 1.50 s lead and is running at a constant speed of 3.25 m/s. The runner has 30.0 m to run before reaching the end of the track. A second runner moves in the same direction as the leader. What constant speed must the second runner ...
*February 27, 2014 by Brady*

**physics**

When an earthquake occurs, two types of sound waves are generated and travel through the earth. The primary, or P, wave has a speed of about 8.0 km/s and the secondary, or S, wave has a speed of about 4.5 km/s. A seismograph, located some distance away, records the arrival of ...
*December 5, 2014 by Anonymous*

**Physics Urgent!!!**

The 1994 Winter Olympics included the aerials competition in skiing. In this event skiers speed down a ramp that slopes sharply upward at the end. The sharp upward slope launches them into the air, where they perform acrobatic maneuvers. In the women's competition, the end of ...
*February 1, 2007 by Samantha*

**physics**

A 0.349 kg particle slides around a horizontal track. The track has a smooth, vertical outer wall forming a circle with a radius of 1.68 m. The particle is given an initial speed of 8.66 m/s. After one revolution, its speed has dropped to 6.05 m/s because of friction with the ...
*February 25, 2014 by Jake*

**math**

Two trains are on the same track a distance 100 km apart heading towards one another, each at a speed of 50 km/h. A fly starting out at the front of one train, flies towards the other at a speed of 75 km/h. Upon reaching the other train, the fly turns around and continues ...
*December 7, 2014 by Rohit*

**PHYSICS**

An entertainer juggles balls while doing other activities. In one act, she throws a ball vertically upward, and while it is in the air, she runs to and from a table 5.50m away at a constant speed of 2.50m/s, returning just in time to catch the falling ball. (a)With what ...
*July 13, 2010 by Francis*

**physic**

A girl throws a stone from a bridge. Consider the following ways she might throw the stone. The speed of the stone as it leaves her hand is the same in each case. Case A: Thrown straight up. Case B: Thrown straight down. Case C: Thrown out at an angle of 45° above horizontal. ...
*July 21, 2010 by lisa*

**Physics**

Gayle runs at a speed of 3.80 m/s and dives on a sled, initially at rest on the top of a frictionless snow covered hill. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back and together they continue down the hill. ...
*October 17, 2010 by A*

**Physics URGENT!!!**

Gayle runs at a speed of 9.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snow-covered hill, that has a vertical drop of 20.0 m. After she has descended a vertical distance of 4.00 m, her brother, who is initially at rest, hops on her back, and ...
*October 17, 2012 by Anonymous*

**Physics URGENT!!!**

Gayle runs at a speed of 9.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snow-covered hill, that has a vertical drop of 20.0 m. After she has descended a vertical distance of 4.00 m, her brother, who is initially at rest, hops on her back, and ...
*October 19, 2012 by Anonymous*

**Projectile physics**

The average speed of a nitrogen molecule in air is about 6.70 ✕ 102 m/s, and its mass is about 4.68 ✕ 10-26 kg. (a) If it takes 3.80 ✕ 10-13 s for a nitrogen molecule to hit a wall and rebound with the same speed but moving in an opposite direction (...
*February 13, 2014 by Joe*

**physics**

Gayle runs at a speed of 3.80 m/s and dives on a sled, initially at rest on the top of a frictionless snow covered hill. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back and together they continue down the hill. ...
*October 8, 2015 by jovelyn trocio*

**physics**

gayle runs at a speed of 4.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snow-covered hill. after she has descended a vertical distance at a 5.00 m, her brother,who is initially at rest, hops on her back, and they continue down the hill together, ...
*October 8, 2015 by naome*

**Health**

Armando's coach is going to be late for soccer practice. As the team captain, it is Armando's responsibility to lead the teams for their warm-up activities. To prepare his team, Armando should direct his team to do which of the following? a. jog around the field, specific body...
*October 31, 2013 by Anonymous*

**math a little less**

celia writes the equation d=8t to represent the distance in miles d that bikers could travel in t hours at a speed of 8 miles per hour. make a table that shows the distance traveled every half hour,up to 5 hours if bkikers ride at this constant speed. how far would bikers ...
*October 2, 2006 by chemiii*

**physics(URGENT!!!!!)**

A meteorite of mass m= 2 ×104 kg is approaching head-on a planet of mass M= 7 ×1029 kg and radius R= 5 ×104 km. Assume that the meteorite is initially at a very large distance from the planet where it has a speed v0= 5 ×102 km/s. Take G= 6.67 ×10−...
*November 2, 2013 by Anonimus*

**Physics **

An astronaut of mass 84.0 kg is taking a space walk to work on the International Space Station. Because of a malfunction with the booster rockets on his spacesuit, he finds himself drifting away from the station with a constant speed of 0.570 m/s. With the booster rockets no ...
*April 8, 2014 by Jason*

**Physics**

Light-rail passenger trains that provide transportation within and between cities are capable of modest accelerations. The magnitude of the maximum acceleration is typically 1.3 m/s ^2, but the driver will usually maintain a constant acceleration that is less than the maximum...
*February 4, 2013 by Aubree*