Monday

August 31, 2015
Number of results: 13,008

**physics**

The flow rate of a liquid through a 2.0cm radius pipe is 0.0080 m^3/s. the average fluid in the pipe is? i know that Av=volume flow rate for this problem the flow rate is 0.008m^3/s. Do i divide by the radius^2 to get velocity or is there someother equation im supposed to be ...
*November 11, 2007 by BrOwN GuRL*

**Physics**

a barrel of oil at rest has a mass of 65kg it is rolled down a 1.2m ramp. Due to constant force exerted on it, the barrel reaches a velocity of 4.2 m/s upon leaving the ramp. Find the constant force on the barrel while it is on the ramp? Help please.
*August 8, 2011 by Tyners*

**Physics**

In the device a 50g mass is hung from a pulley and released. A disk is placed on the platform. The platform has a radius of 5cm. The disk and platform go from rest to an angular velocity of 8.5rad/s in 2.5 seconds. What is the moment of inertia of the disk? What is its mass? ...
*April 6, 2014 by Joe*

**physics**

A person of mass 60 kg is standing on a raft of mass 40kg in a lake. The distance of a person from bank is 30m. If a person starts running towards bank with velocity 10m/s then his distance from bank after 1s will be ?? And explain with diagram and proper steps
*September 16, 2014 by saira*

**physics**

Two cars are driving toward each other on a straight, flat Kansas road. The Jeep Wrangler is traveling at 84 km/h north and the Ford Taurus is traveling at 43 km/h south, both measured relative to the road. What is the velocity of the Jeep relative to an observer in the Ford?
*October 3, 2007 by stephanie*

**Physics**

Suppose the water near the top of Niagara Falls has a horizontal speed of 2.3 m/s just before it cascades over the edge of the falls. At what vertical distance below the edge does the velocity vector of the water point downward at a 55° angle below the horizontal?
*April 1, 2008 by Will*

**calculus**

The height (in feet) of a skydiver at time t (in seconds) after opening his parachute is given by h(t) = 4000 – 19t. Find the skydiver's velocity after the parachute opens. The answer should be in feet per seconds. I would appreciate if somebody helps.... Thank you.
*September 21, 2010 by Mark*

**physics**

Suppose the water near the top of Niagara Falls has a horizontal speed of 2.7 m/s just before it cascades over the edge of the falls. At what vertical distance below the edge does the velocity vector of the water point downward at a 72° angle below the horizontal?
*October 13, 2010 by megan*

**Trig**

An airplane is flying on a compass heading (bearing) of 340 degrees at 325 mph. A wind is blowing with the bearing 320 degrees at 40 mph. Find the component form of the velocity of the airplane. then find the actual ground speed and direction of the plane
*December 17, 2010 by K*

**physics**

Two cars are driving toward each other on a straight, flat Kansas road. The Jeep Wrangler is traveling at 84 km/h north and the Ford Taurus is traveling at 43 km/h south, both measured relative to the road. What is the velocity of the Jeep relative to an observer in the Ford?
*February 3, 2011 by cindy*

**physics**

a 65 kg object is pulled at a constant velocity up an incline w/ a force of 95 N parallel to the incline. Assuming that the difference between the work output and input is work required to overcome friction, what is the force of friction along the incline (the length of the ...
*April 8, 2011 by Jun*

**calculus**

An object moves along the x-axis, according to x= (pi/2)t + sin(pi t). a) What is the largest velocity such an object attains? b) Identify one interval on which the object is accelerating in a positive direction. Explain your reasoning. c) Name one part of that interval for ...
*January 26, 2012 by pleh*

**Trig.**

Josh kicks a soccer ball with an initial velocity of 18 feet per second out of a window from a height of 12 feet. The function h(t)= -16t^2+18t+12 represents the height of the soccer ball after t seconds.What is the domain of this function in the context of this problem?
*April 1, 2012 by Rach*

**Physics**

4. What does the slope of each of the following graphs stand for? (y versus x) a) mass vs volume b) velocity vs time c) mass vs force d) kinetic energy vs frequency e) sine incident angle vs sine refracted angle f) charge vs voltage g) voltage vs current h) force vs area
*April 11, 2013 by Alexis*

**physics**

A rescue helicopter is lifting a man (weight = 925 N) from a capsized boat by means of a cable and harness. (a) What is the tension in the cable when the man is given an initial upward acceleration of 2.59 m/s2? (b) What is the tension during the remainder of the rescue when ...
*June 30, 2013 by ashley*

**Physics**

A charged particle is projected into a uniform B-field. Its velocity vector is perpendicular to the B-field vector. What type of path will the particle travel? Neglect gravity. Answer straight line motion elliptical motion parabolic motion circular motion
*July 16, 2013 by tom*

**Physics**

A plane is flying horizontally with speed 251 m/s at a height 2180 m above the ground, a package is thrown downward from the plane with a vertical speed v1 = 80 m/s. What is the magnitude of the total velocity of the package at the moment it is thrown as seen by an observer on...
*November 7, 2014 by Kyle*

**Trig**

a ships navigator determines that the ship is moving through the water at 17.5mi/h with a heading of 26.3 degrees north of east but the ship is actually moving at 19.3 mi/h in a direction of 33.7 degrees north of east. What is the velocity of the current? would this be 17....
*December 1, 2014 by Erica*

**nature of science**

which of the following best explains velocity? A.the speed & direction of an object in motion C.only the change of direction of an object in motion D.the direction of an object in motion
*November 15, 2013 by science*

**Physics**

A 14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. Find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earth’s velocity. Earth’s mass is 6.0 × 1024 kg. Show all your work, assuming the...
*January 27, 2012 by Pat*

**Physics**

2) The baseball player throws a curve ball that reaches the catcher in 0.60 seconds. The ball curves because it is spinning at an average angular velocity of 330 rev/min (assumed constant) on its way to the catcher's mitt. What is the angular displacement of the baseball (in ...
*December 21, 2009 by Mike*

**phsics**

A coin with a diameter of 1.9 cm is dropped on edge onto a horizontal surface. The coin starts out with an initial angular speed of 19 rad/s and rolls in a straight line without slipping. The rotation slows with an angular acceleration of magnitude 2.1 rad/s2. What is the ...
*September 27, 2010 by help*

**Physics**

A mine shaft is known to be 57.8 m deep. If you would drop a rock down the shaft, how long would it take for you to hear the sound of the rock hitting the bottom of the shaft knowing that sound travels at a constant velocity of 345 m/s? The answer is 3.60s, but I need to work ...
*October 11, 2010 by Alina*

**physics **

A car rolls down a 13.0° slope for 50.0 m, accelerating at 2.90 m/s2. Leaving the cliff at 13.0° below the horizontal, with the velocity it acquired from rolling downhill, the car falls 26.0 m to the rocks below, bursting into flame upon impact. What horizontal distance from ...
*October 30, 2010 by john*

**physics help**

The magnitude of the velocity of a particle which starts from rest 2 ft below the origin when t = 0 and moves along a vertical axis is directly proportional to the time after starting. The displacement of the particle during the time interval from t = 1 sec to t = 2 sec is 3 ...
*January 20, 2011 by stan*

**physics help**

The magnitude of the velocity of a particle which starts from rest 2 ft below the origin when t = 0 and moves along a vertical axis is directly proportional to the time after starting. The displacement of the particle during the time interval from t = 1 sec to t = 2 sec is 3 ...
*January 20, 2011 by stan*

**physics**

A tennis ball of mass 0.057 kg is served. It strikes the ground with a velocity of 54 m/s (120 mph) at an angle of 21° below the horizontal. Just after the bounce it is moving at 51 m/s at an angle of 19° above the horizontal. If the interaction with the ground lasts 0.064 s, ...
*August 2, 2011 by Ashley*

**College Physics**

A cable attached to a block of mass 16.35 kg pulls the block along a horizontal floor at a constant velocity. If the tension in the cable is 9.36 N, what is the coefficient of kinetic friction between the block and the floor? not sure how to do this one ... I am thinking I use...
*September 12, 2011 by Anon*

**physics**

If an airplane propeller rotates at 1570 rev/min while the airplane flies at a speed of 333 km/h relative to the ground, what is the linear speed of a point on the tip of the propeller, at radius 1.97 m, as seen by (a) the pilot and (b) an observer on the ground? The plane's ...
*November 9, 2011 by kyle*

**math**

Please explain to work this: A rocket is launched from atop a 105-foot cliff with an initial velocity of 156ft/s. the height of the rocket above the ground at time t is given by h= -16t^2 + 156t + 105. When will the rocket hit the ground after it is launched? Round to the ...
*April 13, 2012 by Mary*

**physics word problem**

A 60.0 kg girl stands up on a stationary floating raft and decides to go into shore. She dives off the 180 kg floating raft with a velocity of 4.0 m/s [W]. Ignore the substantial friction real objects in water experience. What is the speed of the raft just after the girl dives?
*July 4, 2014 by Liz*

**Physics**

A 10 kg box is pulled across the floor at a constant velocity of 3.0 m/s. If the box is pulled with a force of 40 N, what is the size of the frictional force between the box and the floor?
*September 30, 2010 by katelyn*

**Physics**

A 10 kg box is pulled across the floor at a constant velocity of 3.0 m/s. If the box is pulled with a force of 40 N, what is the size of the frictional force between the box and the floor?
*October 18, 2010 by Diana*

**Physics**

A 10 kg box is pulled across the floor at a constant velocity of 3.0m/s. If the box is pulled with a force of 40 N, what's the size of the frictional force between the box and the floor?
*October 18, 2010 by Diana*

**Physics**

A basketball player, standing near the basket to grab a rebound, jumps 73.6 cm vertically. How much time does the player spend in the bottom 15.4 cm of the jump? I need someone to check my work. I got about 3.797 as the inital velocity. I plugged this into "x = vt + 1/2at^2" ...
*October 10, 2007 by Lindsay*

**Integration**

The velocity v(t) = x'(t) at time t of an object moving along the x axis is given, along with the initial position x(0) of the object. In each case, find: 5) x'(t) = 1/((2t + 1)^(1/2)); x(0) = 0 a) the position x(t) at time t I found that x(t) = (2t + 1)^{1/2) - 1 c) The time ...
*February 11, 2009 by Anonymous*

**physics**

A box of mass 11.9 kg is pulled to the right with a horizontal force of 11.3 N. The box moves to the right with constant velocity, 1.6 m/s. Determine the amount of working the pulling force and the normal force do if the box moves 5.7 m.
*December 9, 2009 by Cory *

**physics **

A charge of -8.9 µC is traveling at a speed of 7.8 106 m/s in a region of space where there is a magnetic field. The angle between the velocity of the charge and the field is 60°. A force of magnitude 4.0 10-3 N acts on the charge. What is the magnitude of the magnetic field?
*February 5, 2011 by Anonymous*

**Physics**

A boy of mass 49.4 kg is initially on a skateboard of mass 2.00 kg, moving at a speed of 10.3 m/s. The boy falls off the skateboard, and his center of mass moves forward at a speed of 10.9 m/s. Find the final velocity of the skateboard.
*October 16, 2011 by Kellie*

**Physics**

You like to swim at a nearby lake. On one side of the lake is a cliff, and the top of the cliff is 69 m above the surface of the lake. You dive of the cliff doing somersaults so as to have an angular speed of 5.5 rev/s. How many revolutions do you make before you hit the water...
*October 11, 2011 by Anon*

**physics**

A block of mass 3 kg initially at rest is pulled along a friction less horizontal surface with a force of 4N. The speed of the block at t=2s is a)4/3 m/s b)8/3m/s c)4 m/s d)8m/s e)24m/s For this problem this is a graph. Some of the points on the graph are (0,0),(1,2),(2,4),(3,...
*December 29, 2006 by me*

**College Math II**

If a ball is tossed into the air from a height of 6 feet with a velocity of 32 feet per second, then its altitude at time t (in seconds) can be described by the function A(t) = - 16t^2 + 32t + 6. Find the altitude of the ball at 2 seconds. I am having problems understanding ...
*November 21, 2009 by Lori*

**physics**

Camping equipment weighing 6000 N is pulled across a frozen lake by means of a horizontal rope. The coefficient of kinetic friction is 0.05. The work done by the campers in pulling the equipment 1000 m at constant velocity is: We never utilized friction this chapter so I don't...
*October 13, 2010 by Spider*

**Physics 20**

dynamics A curling stone has a mass of 20kg. a curler pushed the stone across the ice to launch it down the rink. a)if the curler starts to move the stone by pushing it with 15N, what is the stones initial acceleration? b)once moving, how much force is required to keep the ...
*April 6, 2011 by bob*

**Physics 20**

dynamics A curling stone has a mass of 20kg. a curler pushed the stone across the ice to launch it down the rink. a)if the curler starts to move the stone by pushing it with 15N, what is the stones initial acceleration? b)once moving, how much force is required to keep the ...
*April 6, 2011 by peter*

**college physics**

Consider a projectile that is thrown upward at an angle between 10 and 80 degrees from the horizontal, when are the acceleration and velocity vectors perpendicular to each other? (Only consider the motion during free fall.) a) nowhere b)at the highest point c)the launch point ...
*April 18, 2012 by CLARE*

**physics**

Engineers are developing new types of guns that might someday be used to launch satellites as if they were bullets. One such gun can give a small object a velocity of 2.9 km/s, moving it through only 1.6 cm. (a) What acceleration does the gun give this object? (b) Over what ...
*October 23, 2012 by miranda*

**Pre-Calculus**

A pomegranate is thrown from a ground level straight up into the air at time t = 0 with velocity 67 feet per second. Its height at time t seconds is f(t)=-16^2+67t. (a) Find the time it hits the ground and (b) the time it reaches its highest point. (c) What is the maximum ...
*January 31, 2013 by Becky*

**Physics**

When a cannon with a longer barrel is fired, the force of expanding gases acts on the cannonball for a longer distance. What effect does this have on the velocity of the emerging cannonball? (Do you see why long-range cannons have such long barrels?) Please help; need a ...
*April 25, 2013 by Chris*

**Physics**

The helicopter in the drawing is moving horizontally to the right at a constant velocity. The weight of the helicopter is W=54300 N. The lift force L generated by the rotating blade makes an angle of 21.0° with respect to the vertical. (a) What is the magnitude of the lift ...
*October 27, 2014 by Candice*

**math**

A baseball player hits a high pop-up with an initial upward velocity of 30 m/s, 1.4 m above the ground. The height, h, in metres, of the ball t seconds after being hit is modelled by the function h(t) = -4t^2+30t+1.4. How long does a player on the opposing team have to get ...
*January 22, 2015 by Alex*

**Physics**

A golf ball released from a height of 1.80 m above a concrete floor, bounces back to a height of 1.06 m. If the ball is in contact with the floor for 4.62 ms, what is the magnitude of the average acceleration a of the ball while it is in contact with the floor? Do I need to ...
*October 4, 2007 by Lindsay*

**physics**

Veronica angrily throws an engagement ring straight up the roof of a building 12m above the ground with an initial speed of 6m/s from the ground to the hand.(a)calculate the average velocity of the ring (b)calculate the height from the ground to the maximum height attained by ...
*February 5, 2012 by Clever watson chindumba*

**physics**

A rock is tossed straight up with a speed of 29m/s. When it returns, it falls into a hole 13m deep. Solve for rock's velocity as it hits the bottom of the hole. &How long is the rock in the air, from the instant it is released until it hits the bottom of the hole?
*June 12, 2012 by Amanda*

**Physics 1**

On a spacecraft, two engines are turned on for 910 s at a moment when the velocity of the craft has x and y components of v0x = 5710 m/s and v0y = 7490 m/s. While the engines are firing, the craft undergoes a displacement that has components of x = 5.78 x 106 m and y = 6.17 x ...
*February 3, 2014 by anonymous*

**physics**

On a spacecraft, two engines are turned on for 910 s at a moment when the velocity of the craft has x and y components of v0x = 5710 m/s and v0y = 7490 m/s. While the engines are firing, the craft undergoes a displacement that has components of x = 5.78 x 106 m and y = 6.17 x ...
*February 3, 2014 by anonymous*

**physic 1**

On a spacecraft, two engines are turned on for 910 s at a moment when the velocity of the craft has x and y components of v0x = 5710 m/s and v0y = 7490 m/s. While the engines are firing, the craft undergoes a displacement that has components of x = 5.78 x 106 m and y = 6.17 x ...
*February 4, 2014 by Anonymous*

**physics**

On a spacecraft, two engines are turned on for 525 s at a moment when the velocity of the craft has x and y components of v0x = 4780 m/s and v0y = 8850 m/s. While the engines are firing, the craft undergoes a displacement that has components of x = 3.54 x 106 m and y = 7.77 x ...
*October 2, 2014 by Julie*

**physics**

If instead, the swimmer makes 30.5 laps in the same pool in 3 h, determine the total distance the swimmer traveled, the swimmer's total displacement, the swimmer's average velocity, and the swimmer's average speed. pool is 30 m long please answer in km
*January 27, 2012 by lauren*

**physics**

If instead, the swimmer makes 30.5 laps in the same pool in 3 h, determine the total distance the swimmer traveled, the swimmer's total displacement, the swimmer's average velocity, and the swimmer's average speed. pool is 30 m long please answer in km
*January 27, 2012 by lauren*

**Physics**

A cannonball is dropped overboard from a boat. The cannonball sinks toward the bottom of the sea. The mass of the seawater displaced by the cannonball is exactly 2/3 the mass of the cannonball. Find the velocity of the cannonball after 10 seconds after being dropped.
*May 7, 2014 by Wong*

**physics**

a projectile is ejected from a 25 m high tower with a velocity of 40 m/s at an angle of 30 degrees to the horizontal first on Earth and then on Mars. What is the ratio of the time taken to hit the ground on Mars compared to Earth? (Assume gravity on mars = .38gEarth) The ...
*January 27, 2014 by kjean*

**physics **

the peregrine falcon is the world's fastest known bird and has been clocked driving downward toward its pray at a constant vertical velocity of 97.2 meters per second. If the falcon drives straight down from a height of 100 meters, how much time does this give a rabbit below ...
*September 11, 2014 by baylie*

**IPC**

A hailstone traveling with a velocity of 43 meters/second comes to a virtual stop 0.28 seconds after hitting water. What is the magnitude of its acceleration in the water? a. 12 meters/second2 b. 1.5 × 102 meters/second2 c. 78.6 meters/second2 d. 6.5 × 10-3 meters/second2
*February 6, 2015 by justin*

**Physics**

1)When does a magnetic field induce maximum EMF in a wire moving with a constant velocity? when the wire is moved at right angles to the magnetic field. 2)Which rule is used to find the direction of force produced by electromagnetic induction? fourth right-hand rule
*April 11, 2008 by Jon*

**physics**

A softball of mass 0.220 kg that is moving with a speed of 6.5 m/s (in the positive direction) collides head-on and elastically with another ball initially at rest. Afterward it is found that the incoming ball has bounced backward with a speed of 4.8 m/s. Calculate the mass of...
*December 9, 2009 by Shane*

**chemistry**

A sample of gas has increased in temperature from 20° Celsius to 22° Celsius. Which of the following happens as the temperature of the gas goes up? A.The gas undergoes a phase change. B. The velocity of the gas particles decreases. C.The kinetic energy of the particles ...
*July 29, 2011 by kendra*

**physics**

A fox is chasing a bunny. The bunny is initially hopping east at 7 m/s when it first sees the fox. Over the next half second the bunny changes its velocity to west at 12 m/s and escapes. What was the bunny's average acceleration (magnitude and direction) during this half-...
*October 10, 2012 by Patsy*

**physics**

car a with mass of 1250kg, is traveling at 30 m/s to the east. car b is a truck with mass of 2000kg, traveling to the west at 25m/s. assume these two vehicles experience an inelastic collision but do not stick together and car a goes off 10m/s to the west. what will be the ...
*January 18, 2013 by mauro dar*

**Physics**

A rescue helicopter is lifting a man (weight = 797 N) from a capsized boat by means of a cable and harness. (a) What is the tension in the cable when the man is given an initial upward acceleration of 0.711 m/s2? (b) What is the tension during the remainder of the rescue when ...
*March 20, 2013 by Kelly*

**Physics**

A rescue helicopter is lifting a man (weight = 797 N) from a capsized boat by means of a cable and harness. (a) What is the tension in the cable when the man is given an initial upward acceleration of 0.711 m/s2? (b) What is the tension during the remainder of the rescue when ...
*March 20, 2013 by Heather*

**Science - Please Check my Answer**

My problem: A swimmer travels from the south end to the north end of a 30.0 m pool in 15.0 s and makes the return trip to the starting position in 19.0 s. What is the average velocity for the second half of the swim? My answer: 1.60 m/s to the south Please check! I will really...
*February 27, 2014 by Brady*

**Physics**

A wheel of moment of inertia 0.136 kg · m2 is spinning with an angular speed of 5000 rad/s. A torque is applied about an axis perpendicular to the spin axis. If the applied torque has a magnitude of 67.8 N · m, the angular velocity of precession will be? Please help me solve ...
*March 28, 2014 by kjean*

**physics**

A jet plane is flying horizontally with a speed of 500 m/s over a hill that slopes upward with a 3% grade (i.e., the "rise" is 3% of the "run"). What is the component of the plane's velocity perpendicular to the ground? (Assume the +x-direction is up along the slope and the +y...
*May 24, 2014 by Soh*

**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^...
*October 31, 2014 by Rose*

**Physics**

A small bag of sand is released from an ascending hot-air balloon whose upward constant velocity is v0 = 1.45 m/s. Knowing that at the time of the release the balloon was 70.3 m above the ground, determine the time, τ, it takes the bag to reach the ground from the moment ...
*February 2, 2015 by Breauna*

**Physics**

A simple wheel and axle is used to life a bucket out of a well. The radii of the wheel and axle are 20 cm and 4 cm, respectively. Determine: 1. The velocity ratio (and so the IMA), 2. The thoretical effort required to life a load of 30 N assuming no energy loosses, 3. The ...
*March 5, 2015 by Eleni*

**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 angle ...
*April 17, 2015 by alexa*

**physics**

a 2000kg car travelling west with a speed of 20m/s collides at an intersection with a 3000kg car travelling south at a speed of 20m/s. find the direction and magnitude of the velocity of the wreckage after the collision, assuming the collision was perfectly inelastic(that is, ...
*July 7, 2015 by Mostafa*

**Physics**

A cannon is mounted on a truck that moves forward at a speed of 5 m/s. The operator wants to launch a ball from a cannon so the ball goes as far as possible before hitting the level surface. The muzzle velocity of the cannon is 50 m/s. What angle from the horizontal should the...
*February 17, 2013 by Brian*

**PHYSICS**

A particle confined to motion along the x axis moves with constant acceleration from x = 2.0 m to x = 8.0 m during a 2.5-s time interval. The velocity of the particle at x = 8.0 m is 2.8 m/s. What is the acceleration during this time interval?
*September 15, 2008 by Ami*

**Science**

A car of mass m travelling at 20 m/s east on a straight level road and a truck of mass 2m travelling at 20 m/s west on the same road. What is the velocity of the car relative to the truck?
*February 7, 2013 by Melvin*

**physics**

A tallest vocano in the Solar System is the 24 km tall Martian volcano, Olympus Mons. Assume an astronaut drops a ball off the rim of the crater and that the free fall acceleration remains constant throughout the ball's 24 km fall at a value of 3.7m/s^2. Find (a) the time for ...
*September 15, 2007 by Anonymous*

**physics**

james made a very nice play on 13 hole on 2011 master's open. he made driver shot with initial velocity 200 m/s. the ball has a mass of 46g. its lunching angle is 28 degrees from the ground. draw the trajectory (x-y graph) with and without air resistance. the air resistance is...
*May 2, 2011 by sam*

**trigonometry**

4.if cotθ = -√15/7 , use the fundamental identities to find cosθ > 0 9.A projectile is fired with an initial velocity of 88 ft/sec at an angle of 35° to the horizontal. Neglecting air resistance, what is the time of impact? (Round to the nearest tenth of a...
*December 13, 2012 by Emily*

**Physics**

A fully loaded elevator weighing 2000 lbs accelerates upward from rest, attaining its rated velocity of 20 fps upon reaching a height of 25 ft. Solve for the tension on the cable lifting the elevator. What is the minimum required power of the lifting motor if 10% is allowed ...
*August 5, 2015 by Aries*

**physics**

A bicyclist moving at a constant speed takes 10.0 seconds to travel 500 meters down a path inclined 30.0° downward from the horizontal. What is the vertical velocity of this motion?Select one of the options below as your answer: A. 18.3 meters/second B. 43.3 meters/second C. ...
*May 25, 2012 by Anonymous*

**Physics**

If a rod is moving at a velocity equal to 1/2 the speed of light parallel to its length, what will a stationary observer observe about its length? The length of the rod will become exactly half of its original value. The length of the rod remains the same. The length of the ...
*October 23, 2012 by Laurie*

**physical**

A 0.8 kg block of wood has an initial velocity of 0.25 m/s as it begins to slide across a table. The block comes to rest over a distance of 0.72m. a) what is the average frictional force on the block? b)How much work is done on the block by friction? c)How much work is done on...
*August 17, 2012 by sara*

**science**

a bicyclist and his bike have a combined mass of 105 kg. He is traveling at 15.0 m/s along the path when he sees a fallen tree 4 m in front of him. In order to stop before hits the tree, find the boy's minimum acceleration and the minimum force that must be applied. Thank You...
*December 30, 2006 by leafprincess*

**Physics**

A robot probe drops a camera off the rim of a 239 m high cliff on Mars, where the free-fall acceleration is -3.7 m/s^2. a) Find the velocity with which the camera hits the ground. b) Find the time required for it to hit the ground. Ok so I'm not even sure of which equation to ...
*September 25, 2007 by Lindsay*

**Physics**

(a) Calculate the kinetic energy that the earth has because of its rotation about its own axis. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used in the United States in one year is about 9.33e9 Joules...
*November 2, 2008 by Kyle*

**Physics**

A rock is dropped from a sea cliff and the sound of it striking the ocean is heard 3.9 s later. If the speed of sound is 340 m/s, how high is the cliff? i know you use the equation y=(initial velocity)(time) + (1/2)(acceleration)(time^2) but I'm having problems putting all the...
*July 2, 2012 by Marissa*

**PHYSICS 1 ..'''''''''''''''''''''''' helllpppppppp**

The “Vomit Comet.” In Zero-gravity astronaut training equipment testing, NASA ﬂies a KC135A aircraft along a parabolic ﬂight path. As shown in Figure P4.47, the air-craf climbs from 24000ft to 31000ft,where it enters a parabolic path with a velocity of 143m/s at ...
*January 9, 2013 by JORHO*

**Physics **

I need to determine maximum tension/down force with a pendulum. I need to use the lightest string possible to: -support a 16kg bob, with -a velocity of 4m/s -with a swing radius of 2m -at it's equilibrium (ie 0 degrees) -given standard gravity. using T=m(V^2/r)+(g*cos(x)) The ...
*October 7, 2014 by Matt*

**Physics**

A young girl (m= 30 kg) rides a skateboard (m= 3.2 kg) at a speed of 4.2 m/s. (a) How much work does the girl have to do to bring herself to a stop? (b) How far does she travel if it takes 6.0 s to stop? (c) What is the magnitude of the stopping force? So I know W=Fd but I am...
*October 9, 2014 by Marin*

**Physics**

Hi! i am going to apply for a medical study admission test and where just wondering if you guys could help me to come up with the formula for solving this problem. I am not looking for a answer, just the mathematical formula to solve theese kind of questions. The question is ...
*May 13, 2015 by Marius*

**Physics**

A model rocket is launched vertically upward from the ground. After 4.3s, its fuel is completely burned. Assume uniform acceleration of 3.0 m/s2 while the fuel is burning. What is the velocity of the rocket at the instant that the fuel is completely burned? What's the rocket's...
*January 4, 2012 by Leasha*

**Physics**

1. On a spacecraft, two engines are turned on for 648 s at a moment when the velocity of the craft has x and y components of v0x = 4360 m/s and v0y = 6270 m/s. While the engines are ﬁring the craft undergoes a displacement that has components of x = 4.11 × 106 m and y...
*October 1, 2012 by Thomas*

**math **

a rock is thrown straight up in the air from an initial height of ho, in metres, with the initial velocity vo, in metres per second. The height in metres above the ground after t seconds is given by h(t) = -4.9t^2 + vo + ho. Find an expression for the time it takes the rock to...
*November 29, 2013 by Kp*