Saturday

October 25, 2014

October 25, 2014

Number of results: 11,793

**Physics**

A 1600-kg car experiences a combined force of air resistance and friction that has the same magnitude whether the car goes up or down a hill at 32 m/s. Going up a hill, the car's engine produces 54 hp more power to sustain the constant velocity than it does going down the same...
*October 15, 2012 by Sam*

**Physics**

A 1800-kg car experiences a combined force of air resistance and friction that has the same magnitude whether the car goes up or down a hill at 28 m/s. Going up a hill, the car's engine produces 52 hp more power to sustain the constant velocity than it does going down the same...
*October 15, 2012 by Darren*

**Physics**

An airplane dropping supplies to northern villages that are isolated by severe blizzards and cannot be reached by land vehicles. The airplane is flying at an altitude of 785m and at a constant horizontal velocity of 53.5 m/s. At what horizontal distance before the drop point ...
*October 4, 2014 by Han*

**physics 12**

im stuck i have no clue where to start, please help me i just know the givens and some claculations. question: kevin stands on he top of a buiulding and he throws an aboject up into the air at a velocity of 16.0m/s at an angle of 25 degrees to the horizontal. if the building ...
*August 8, 2010 by priya*

**maths(urgent....please...)**

1) A ball is hit at an angle of 36 degrees to the horizontal from 14 feet above the ground. If it hits the ground 26 feet away (in horizontal distance), what was the initial velocity? Assume there is no air resistance. i have posted the same question earlier and i got some ...
*April 12, 2011 by arun*

**pyhsic question for count iblis**

PLEASE GIVE THE ANSWER,I ALREADY INPUT TO YOUR FORMULA AND IT IS FALSE... Is your answer 0.57? A 15 kg, 1m wide door which has frictionless hinges is closed but unlocked. A 400 g ball hits the exact middle of the door at a velocity of 35 m/s and bounces off elastically, ...
*May 22, 2013 by pyhsiclover*

**phys**

An electron of kinetic energy 50 keV moves in a circular orbit perpendicular to a magnetic field of 0.405 T. Find the radius of the orbit. I tried using KE=mv^2/2 to find velocity. then using qBv=(mv^2)/r to solve for r. but my answer was wrong. I am pretty sure this is the ...
*October 14, 2014 by sara*

**Physics**

Part 1: Two balls (Ball 1 and Ball 2) are released from the top of a tower. Ball 2 is thrown 3.14 seconds after Ball 1 is dropped. Ball 2 is thrown downward with a velocity of 3.49 m/s. Determine how far apart Ball 1 and Ball 2 are after 5.02 seconds from when Ball 1 was ...
*September 12, 2012 by Ashley*

**Physics**

Part 1: Two balls (Ball 1 and Ball 2) are released from the top of a tower. Ball 2 is thrown 3.14 seconds after Ball 1 is dropped. Ball 2 is thrown downward with a velocity of 3.49 m/s. Determine how far apart Ball 1 and Ball 2 are after 5.02 seconds from when Ball 1 was ...
*September 12, 2012 by Ashley*

**Physics**

a plane is flying at a velocity of 5500 km/hr, 55 degrees north of east. How far EAST has it traveled after 4 hours? How far North has it traveled after 4 hours?
*February 10, 2011 by Sara*

**physics**

A 1.79 kg block slides across a horizontal surface directly toward a massless spring with spring constant 5,300 N/m. The surface is frictionless except for a rough patch of length 0.45 m that has coefficient of kinetic friction 0.28. The initial velocity of the block is 3.24 m...
*July 24, 2012 by Mike*

**Physics**

The graph below shows the force applied to a 4.0 kg cart initially at rest but free to move on a horizontal track. Forces (in N) are measured on the ordinate and times (in s) are measured on the abscissa. Use the following values for the graph: a = 4.9 and x = 2.0. Assume the ...
*April 14, 2014 by JAYZ*

**physics**

A cup of coffee is on a table in an airplane flying at a constant altitude and a constant velocity. The coefficient of static friction between the cup and the table is 0.100 . Suddenly, the plane accelerates forward, its altitude remaining constant. What is the maximum ...
*December 13, 2012 by Amy*

**physics**

A 85 kg pole-vaulter falls from rest from a height of 6.4 m onto a foam-rubber pad. The pole-vaulter comes to rest 0.48 s after landing on the pad. (a) Calculate the athlete's velocity just before reaching the pad. m/s downward (b) Calculate the constant force exerted on the ...
*April 21, 2013 by Kat*

**Physics**

A hardworking ant must supply 0.00955 N to pull a small piece of fruit at constant velocity over a distance of 8.60 cm up a small hill to the entrance of the colony. If the coefficient of kinetic friction between the piece of fruit and the 16.2° sloped hill is 0.540, calculate...
*November 3, 2013 by Anonymous*

**Physics**

A hardworking ant must supply 0.00955 N to pull a small piece of fruit at constant velocity over a distance of 8.60 cm up a small hill to the entrance of the colony. If the coefficient of kinetic friction between the piece of fruit and the 16.2° sloped hill is 0.540, calculate...
*November 3, 2013 by Anonymous*

**Physics**

A hardworking ant must supply 0.00955 N to pull a small piece of fruit at constant velocity over a distance of 8.60 cm up a small hill to the entrance of the colony. If the coefficient of kinetic friction between the piece of fruit and the 16.2° sloped hill is 0.540, calculate...
*November 4, 2013 by Anonymous*

**Precalc**

A boat that travels at 16 knots in calm water is sailing across a current of 3 knots on a river 250 m wide. The boat makes an angle of 35 degrees with the current heading into the current. Find the resultant velocity of the boat. How far upstream is the boat when it reaches ...
*April 11, 2008 by Natalie*

**Physics**

6)A 700kg car is travelling at a constant velocity of 35m/s when it slams on the brakes and comes to a stop. How far did the car travel during braking if the coefficient of kinetic friction is 0.62 ? (Hint: if the accelerator is no longer being pressed, is there an applied ...
*October 31, 2009 by Anonymous*

**physics **

A person throws a physics book off of a cliff at an initial speed of 3 m/s at an angle of 20 degrees. The book is in the air for a total of 2.5 seconds. a) How high is the cliff? b) How far away from the base of the cliff does the book land? c) What is the magnitude and ...
*May 11, 2011 by ryan*

**physics**

Three particles, each of mass 3.0 kg, are fastened to each other and to a rotation axis by three massless strings, each 0.360 m long, as shown in the Figure. The combination rotates around the rotation axis with an angular velocity of 19.0 rad/s in such a way that the ...
*March 16, 2012 by Katie*

**Physics**

A 20lb ball is 1 ft. in diameter and has a angular velocity of 300 rpm when it is 2 ft. away from the plate. The coefficient of rolling friction between the surface and the ball is μs = 0.3. It strikes the 1-ft. high, 10-lb plate that is held in place by an unstretched ...
*April 30, 2012 by RON*

**Physics**

A certain car is capable only of accelerat ing at 3.0m/s 2 , braking (decelerating) at 5.0m/s 2 , and moving at constant velocity. The car is init ially located 100m from a road sign. The driver, starting from rest, begins to accelerat e towards the sign. After maintaining ...
*March 20, 2013 by George*

**Physics**

A box weighing 8.0 kg has to be moved from the floor to the back of the truck, using a ramp 2.5 m long inclined at 30°. The worker gives the box a push so that it has initial velocity of 5.0 m/s. Unfortunately, the friction is more than he estimated and the box stops 1.6 m up ...
*March 25, 2013 by Peter*

**physics**

1.)A radio station transmits waves of length 400m.if the speed of the waves is 3*10power8m/sec,find the frequency of the radio station. 2.)Audible range of frequencies is between 20Hz and 20KHz.Find the range of the wavelengths corresponding to these frequencies.given,velocity...
*May 18, 2012 by srikar*

**Grade 12 Calculus **

6. The forward motion of a space shuttle, t seconds after touchdown, is described by s(t) = 189t − t^3, where " is measured in metres. a) What is the velocity of the shuttle at touchdown? b) How much time is required for the shuttle to stop completely? c) How far does ...
*April 15, 2013 by Fadak*

**Grade 12 Calculus **

The forward motion of a space shuttle, t seconds after touchdown, is described by s(t) = 189t − t^3, where " is measured in metres. a) What is the velocity of the shuttle at touchdown? b) How much time is required for the shuttle to stop completely? c) How far does the...
*April 18, 2013 by HELP MEE PLEASE*

**AP physics**

A water skier, moving at a speed of 8.61 m/s, is being pulled by a tow rope that makes an angle of 34.9 ° with respect to the velocity of the boat. The tow rope is parallel to the water. The skier is moving in the same direction as the boat. If the tension in the tow rope is ...
*February 18, 2011 by Johnny*

**Physics**

A river flows due East at 0.979 m/s. A boat crosses the river from the South shore to the North shore by maintaining a constant ve- locity of 12.8 m/s due North relative to the water. The river is 306 m wide. What is the velocity of the boat relative to shore? Answer in units ...
*August 12, 2011 by Nicole*

**physics**

Ann, a 59.2 kg person throws a 0.0435 kg snowball forward with a ground speed of 39.5 m/s. Billy, with a mass of 63.5 kg, catches the snowball. Both people are on skates. Ann is initially moving forward with a speed of 2.22 m/s, and Billy is initially at rest. After the ...
*October 21, 2012 by Anonymous*

**calculus**

The velocity of a skateboard is v(t) = t^2 - 4 t + 3 m/s when moving in a straight line. A. Find the the change in displacement of the skateboard between 4 seconds and 6 seconds. (Note this may or may not be negative, meaning it goes in the opposite direction, if so then be ...
*March 8, 2014 by ricky*

**physics**

A dolphin jumps with an initial velocity of 10.5 m/s at an angle of 32.0° above the horizontal. The dolphin passes through the center of a hoop before returning to the water. If the dolphin is moving horizontally when it goes through the hoop, how high above the water is the ...
*December 10, 2009 by Tom*

**physic**

A dolphin jumps with an initial velocity of 13.0m/s at an angle of 41.0 ^\circ above the horizontal. The dolphin passes through the center of a hoop before returning to the water.If the dolphin is moving horizontally when it goes through the hoop, how high above the water is ...
*July 14, 2012 by aa*

**Physics**

A dolphin jumps with an initial velocity of 13.0at an angle of 44.0 above the horizontal. The dolphin passes through the center of a hoop before returning to the water. If the dolphin is moving horizontally when it goes through the hoop, how high above the water is the center ...
*February 6, 2013 by Meredith*

**Physics**

A dolphin jumps with an initial velocity of 13.0at an angle of 44.0 above the horizontal. The dolphin passes through the center of a hoop before returning to the water. If the dolphin is moving horizontally when it goes through the hoop, how high above the water is the center ...
*February 6, 2013 by Meredith*

**physics**

A 15.0 kg dart is thrown horizontally into a dartboard. The thrower applies a 80.0 N force over a distance of 88.2 cm in order to propel the dart. a) Calculate the work done by the dart thrower. b) Determine the velocity of the dart. c) If the dart went 4.50 cm into the ...
*January 9, 2014 by Alice*

**math**

Your friend is standing below the window outside of our classroom and attempting to throw a rock past the window to get your attention. The rock is thrown straight up in the air and passes our window 0.40s after being released. It passes the same window on its way back down 1....
*February 21, 2014 by gabriela*

**HELP PLEASE**

the wind blowing on a vertical surface varies jointly as the area of the surface and the square of the velocity. if a wind of 40 mph exerts a force of 50 pounds on a surface of 1/2 square foot , how much force will a wind of 80 mph place on a surface of 2 square feet the ...
*October 1, 2007 by Katy*

**science**

a boat heading due north crosses a wide river with speed of 12km/h relative to the water the water in the river has a uniform speed of 5 km/h due east relative to the earth.determine the velocity of the boat relative to an observer standing on either bank and the direction of ...
*July 1, 2012 by jo1475*

**science, absolute zero**

what is absolute zero? if 0 kelvin is the lowest temperature we can ever get, then does it mean that -273 degree Celsius is the lowest temperature we can reach? the book said "when we remove all of the energy from something, its temperature will be zero kelvin", what does ...
*January 17, 2007 by minerva*

**Physics**

At an antique car rally, a Stanley Steamer automobile travels north at 38 km/h and a Pierce Arrow automobile travels east at 51 km/h. Relative to an observer riding in the Stanley Steamer, what are the x- and y-components of the velocity of the Pierce Arrow car?
*February 8, 2010 by Max*

**Physics**

At an antique car rally, a Stanley Steamer automobile travels north at 38 km/h and a Pierce Arrow automobile travels east at 51 km/h. Relative to an observer riding in the Stanley Steamer, what are the x- and y-components of the velocity of the Pierce Arrow car?
*February 9, 2010 by Max*

**physics**

A boy throws a ball at 5.5 m/s at an angle of 25.4° above the horizontal off a cliff which is 70.8 m high. What angle does the velocity of the ball make with the horizontal 0.78 s after the throw? (make the angle positive if the angle is above the horizontal, and negative if ...
*December 6, 2012 by vince*

**Physics**

A ball is thrown straight upward (along the y-axis) with an initial velocity of 16 m/s from the top of a building located 20 m above ground. Find the maximum height of the ball. In other words, find the ball's maximum distance from the ground. Be aware that once you find the ...
*June 20, 2011 by Promise*

**Physics**

1. A rescue plane flying horizontally at an altitude of 500 m and velocity of 300 m\s east drops a food supply packet to plane crash survivors on the ground. The packet falls freely to the ground without a parachute. Assume that the weather is perfect. a. Calculate the time it...
*October 23, 2012 by Shannon*

**Physics **

A plane is ﬂying horizontally with speed 152 m/s at a height 2110 m above the ground, when a package is dropped from the plane. The acceleration of gravity is 9.8 m/s 2 . Neglecting air resistance,A second package is thrown downward from the plane with a vertical speed ...
*December 9, 2012 by Emily*

**Phy**

A 2.0 kg ball is placed against a spring of force constant 750N/m, which has been compressed 0.28m. The spring is released and the ball moves along a horizontal frictionless surface and up a ramp. Calculate the... a) maximum elastic potential energy of the spring (could it be ...
*January 14, 2013 by Shanelle*

**Science (physics)**

A particle P is launched from a point O with an initial velocity of 60m/s at an angle of 30 degrees to the horizontal. At the same time, a second particle Q is projected in the opposite direction with initial speed of 50m/s from a point level with point O and 100m from O. You ...
*March 18, 2013 by Joe*

**Intermediate algebra, concepts and graphs**

a bullet is fired into the air with an initial upward velocity of 64 fps from the top of a building 80 feet high. The equation that gives the height of the bullet at any time (t), is h=80+64t-16t^2. Find the times at which the arrow will be 128 feet in the air? This talks ...
*June 12, 2013 by Lisa*

**physics**

You are riding a carousel that is turning at a constant angular velocity. You must pull toward the center with 100N of force to stay in place. You decide to move radially toward the center of the carousel to ride on a small animal figure that is at half the distance from the ...
*September 23, 2014 by Girma*

**Physics**

An electron that has velocity v = (3 x 105 m/s) and moves along positive x direction through the uniform magnetic field B = (0.8T) which is along the positive z direction. a. Find the force on the electron (magnitude and direction). (e = - 1.6 x 10-19 C, m=9.1 x10-31 kg) b. ...
*April 25, 2011 by asif*

**physics**

A boy sitting on the edge of a vertical cliff fires a rock with a slingshot at a velocity of 16.45758956 m/s and an angle of 59.78 degrees above the horizontal. The rock lands in a lake at the base of the cliff, a horizontal distance of 89.67 meters beyond the base of the ...
*September 14, 2009 by projectile motion*

**physic**

Six roller-coaster carts pass over the same semicircular "bump." The mass M of each cart (including passenger) and the normal force n of the track on the cart at the top of each bump are given in the figures. Iam given the force in N of the cart at the peak of the loop and the...
*October 27, 2010 by mike*

**physics**

A boy sitting in a boat at rest throws a 6.4kg object horizontally out of the boat at 10.0 m/s. The mass of the boy is 26kg and the mass of the boat is 45kg. Calculate the velocity of the boat just after the package is thrown. I used momentum before = momentum after. 6.4kg*10....
*March 18, 2011 by Mark*

**Physics**

A swimmer can swim in still water at a speed of 9.31 m/s. He intends to swim directly across a river that has a downstream current of 4.35 m/s. a) How many degrees from straight across the river should he head? Let upstream be a positive angle. Answer in units of degrees b) ...
*October 11, 2012 by Diego*

**Physics**

The earth moves around the sun in a nearly circular orbit of radius 1.50 x 1011 m. During the three summer months (an elapsed time of 7.89 x 106 s), the earth moves one-fourth of the distance around the sun. (a) What is the average speed of the earth? (b) What is the magnitude...
*September 7, 2013 by WR*

**physics**

A neutron, a proton, and an electron are initially at the same distance from a relatively large stationary nucleus moving at a constant velocity. Assume the masses of the proton and neutron are equal. 1. Which is the first particle to reach the nucleus? 2. Which particle ...
*March 23, 2008 by Karen*

**PHYSICS!!!**

A neutron, a proton, and an electron are initially at the same distance from a relatively large stationary nucleus moving at a constant velocity. Assume the masses of the proton and neutron are equal. 1. Which is the first particle to reach the nucleus? 2. Which particle ...
*March 23, 2008 by Karen*

**physics**

A Hollywood Daredevil plans to jump a canyon on a motorcycle. There is a 15 m drop and the horizontal distance originally planned was 60 m but it turns out the canyon is really 69.6 m across. If he desires a a 3.2 second flight time a. what is the correct angle of his launch ...
*September 11, 2009 by Andy *

**physics **

A Hollywood Daredevil plans to jump a canyon on a motorcycle. There is a 15 m drop and the horizontal distance originally planned was 60 m but it turns out the canyon is really 69.6 m across. If he desires a a 3.2 second flight time a. what is the correct angle of his launch ...
*September 12, 2009 by Andy *

**Physics for life science**

1. A car starts from rest and accelerates at a constant rate to 80km/h in 6s in positive direction. What is the acceleration? 2. After how long will the car speed be 120km/h if it keep accelerating at the same rate as in 1.? 3.After the car reached speed of 120km/h it travels ...
*March 23, 2010 by Simeon*

**phyics**

If two cars are traveling along a straight road, one behind the other. the first is traveling at a constant velocity of 10 m/s. the second, approaching from the rear, is traveling at 22 m/s. when the second car is 300m behind the first, the driver applies the brakes, ...
*November 6, 2010 by billy*

**physics please help me**

A 5.00 kg ball (ball 1), moving to the right at a velocity of +4.00 m/s on a frictionless table, collides head-on with a stationary 7.60 kg ball (ball 2). Find the final velocities of the balls if the collision is as specified below. (a) elastic collision ball 1 = -.825 ball 2...
*November 7, 2010 by dan*

**physics**

There is a 1500 mile race course. I MUST have a top speed of 36 meters/s (meaning I cannot go over 36). The max foward acceleration is 4 m/s squared and the max backward acceleration is 6 m/s squared. I start at 600m and must go to the 800m mark (I must travel 200m). What is ...
*March 14, 2011 by hanna*

**physics **

Marks: 2 The time taken by the space craft moving at a speed equal to half the velocity of light to go from star A to star B is 2 years as calculated at the Earth station. Which of the following is correct for the time measured by the astronaut in the space craft to reach the...
*April 30, 2011 by ashley --*

**physics **

Marks: 2 The time taken by the space craft moving at a speed equal to half the velocity of light to go from star A to star B is 2 years as calculated at the Earth station. Which of the following is correct for the time measured by the astronaut in the space craft to reach the...
*April 30, 2011 by ashley --*

**Physics**

Suppose that a 200g mass (0.20kg) is oscillating at the end of a spring upon a horizontal surface that is essentially friction-free. The spring can be both stretched and compressed and have a spring constant of 240N/m. It was originally stretched a distance of 12cm (0.12m) ...
*March 13, 2012 by Kayla*

**physics**

A water skier, moving at a speed of 6.42 m/s, is being pulled by a tow rope that makes an angle of 39.7 ° with respect to the velocity of the boat (see the drawing). The tow rope is parallel to the water. The skier is moving in the same direction as the boat. If the tension in...
*February 1, 2011 by bam*

**Physics**

A ship is sailing west at 5km/h relative to land.To people on the ship, a balloon appears to move away horizontally at 10km/h versus east. A)what is the wind velocity relative to land? B)What is the distance travelled by the balloon in 30 min 1)For a person at rest on the ship...
*October 8, 2014 by Sabrina*

**Physics**

Starting from rest, a 6.70 kg object falls through some liquid and experiences a resistive (drag) force that is linearly proportional to the velocity of the object. It's measured that the object reaches half its terminal speed at 4.50 s. a) What is the terminal speed for this ...
*July 26, 2012 by Zac*

**physics**

The above graph represents the motion of two vehicles: A and B What is the acceleration of vehicle A during the first 5.0 s? Calculate the distance between vehicle A and B after 6.0 s? What is the instantaneous acceleration of vehicle A at the 10.0 s mark? What is the average ...
*June 3, 2014 by grey*

**physics**

I'm suppose to draw velocity time and acceleration time graph for a rocket that is launched vertically into the air and falls back down to its initial height. We are to assume that x axis is up. So would I draw an curved figure like a downward parabola or a straight vertical ...
*September 5, 2011 by Jennifer*

**Physics help!!**

An archer shoots an arrow with a velocity of 45 m/s at an angle of 50 degrees with the horizontal.An assistant standing on the level ground 150m downrange from the launch point throws an apple straight up with the minimum intial speed necessary to meet the path of the arrow. (...
*February 18, 2013 by Sammie*

**math**

A major leaugue baseball player hits a ball 3 feet above the ground with a velocity of 103 feet per second in the direction of a 10 foot wall that is 300 feet from home plate. If the hit is at an angle of elevation of 34 degrees and there is wind blowing 22 feet per second in ...
*May 14, 2013 by Chris*

**math**

A major leaugue baseball player hits a ball 3 feet above the ground with a velocity of 103 feet per second in the direction of a 10 foot wall that is 300 feet from home plate. If the hit is at an angle of elevation of 34 degrees and there is wind blowing 22 feet per second in ...
*May 14, 2013 by Chris*

**physics**

an airplane with a speed of 40.4 m/s is climbing upward at an angle of 54 degrees with respect to the horizontal. When the planes altitude is 520 m, the pilot releases a package. a. calculate the distance along the ground measured from a point directly beneath the point of ...
*September 23, 2012 by mo*

**acceleration estimate(bobpursley)**

Well, bobpursley explained this to me. I didn't understand this well. Since there was an error in the data, I am posting it again t(sec) v(ft/sec) 1 12.2 1.5 13 2 13.4 2.5 13.7 velocity of an object moving along a line at various times. How do I estimate the object's ...
*December 11, 2006 by Jen*

**physics**

A stone is projected upward at an angle of 60degree to the horizontal from the top of a tower of height 100meter and it hits the ground at a point. If the initial velocity of projection is 100meter. Calculate the maximum height of the stone above the ground. Calculate the time...
*January 3, 2012 by John*

**physics**

A stone is projected upward at an angle of 60degree to the horizontal from the top of a tower of height 100meter and it hits the ground at a point. If the initial velocity of projection is 100meter. Calculate the maximum height of the stone above the ground. Calculate the time...
*January 3, 2012 by John*

**Physics**

The force on an object is described as a function of time equation: F(t) = 3t^2+7t What is the impulse delievered by the force over a period of time from 0 to 5.0s? What is the average force exerted on an object over this time period? If the object has a mass of 2.0kg and is ...
*March 1, 2011 by melissa*

**Physics**

While standing on a frictionless ice surface, a 50 kg skater pushes against a wall with an average force of 150 N west for 0.210 s. Calculate the velocity of the skater at 0.210 s. This was what i did: m = 50 kg Fnet = 150 N t = 0.210 s Vf =? Fnet = ma Fnet/m = a 150 N/50 kg...
*March 28, 2011 by bram*

**Physics**

Units count. Show all steps, not just the numerical substitutions. Show the equations you used. No information is missing. A person throws a ball upward into the air with an initial velocity of 15.0 m/s. Calculate the following: a.) how high it goes. b.) how long the ball is ...
*September 26, 2011 by Jane*

**Physics**

Units count. Show all steps, not just the numerical substitutions. Show the equations you used. No information is missing. A person throws a ball upward into the air with an initial velocity of 15.0 m/s. Calculate the following: a.) how high it goes. b.) how long the ball is ...
*September 26, 2011 by Phil*

**Physics**

I've been stuck on this problem for a while. Im not sure where to even begin. A bike wheel is rotating with an angular velocity of 3.1 rev/s. If the coefficient of kinetic friction between the wheel and brakes is .87, then find the revolutions the wheel makes in coming to rest...
*April 21, 2011 by Ashley*

**Physics**

A hydrogen atom consists of a positively charged proton (nucleus) and a negatively charged electron. The following is correct due to Coulomb's law: a.The two particles repel each other b.The electron accelerates toward the proton c.The electron and proton are in mechanical ...
*February 5, 2010 by Sammy*

**physics**

An airplane with a speed of 13 m/s is climbing upward at an angle of 48° counterclockwise from the positive x axis. When the plane's altitude is 720 m the pilot releases a package. (a) Calculate the distance along the ground, measured from a point directly beneath the point of...
*October 19, 2010 by Anonymous*

**physics**

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 gun has been elevated at è = 18.0° above the horizontal. If the railway gun was at rest ...
*February 28, 2011 by Anonymous*

**Physics**

Philadelphia Flyers player Mike Richards stands on the frictionless ice next to the goal. Neither Mike nor the goal are anchored to the ice. Frustrated after a recent playoff loss, 102.5kg Mike suddenly pushes on the goal, sending it across the ice a 2.80m/s. Mike recoils in ...
*April 29, 2012 by Sarah*

**Physics**

Upon a flat only 10 m high (Is that possible?) there are two guns A and B attached together making a vertical angle of 60 degrees when A is flat on roof. They fire at the same time and has the same reloading time. Both guns are capable of giving an initial velocity of 5√...
*August 10, 2012 by Imalka*

**Differential Equations**

The velocity v of a freefalling skydiver is well modeled by the differential equation m*dv/dt=mg-kv^2 where m is the mass of the skydiver, g is the gravitational constant, and k is the drag coefficient determined by the position of the driver during the dive. (a)Find the ...
*January 24, 2013 by Erica*

**physics**

a hot air balloonist, rising vertically with a constant velocity of magnitude 5m/s releases a sandbag at an instant when the balloon is 40m above the ground. after it is released, the sandbag is in free fall. a) compute position at .250s b.)how many seconds after its release, ...
*July 19, 2008 by anonymous*

**physics**

A cart of mass m = 1.10 kg on a track undergoes a collision with another cart. It's velocity before and after the collision, vi and vf is measured and found to be vi = 2.12¡À0.06 m/s and vf = 0.60¡À0.08 m/s. Calculate the following quantities including their uncertainty. ...
*February 19, 2014 by Chen*

**Psychics**

A freight car is moving freely along a railroad track at 7.0 m/s and collides with a tanker car that is at rest. After the collision, the two cars stick together and continue to move down the track. What is the magnitude of the final velocity of the cars if the freight car has...
*March 17, 2011 by Kendra *

**physics**

a car accelerates from rest at a constant rate 'a' for some time. after which it decelerates at a constant rate'b' and comes to rest. if the total time elapsed is t second, evaluate 1) the maximum velocity reached and 2) the total distance travelled. the answer for this ...
*July 13, 2011 by pavatharani*

**physics**

A subway train starts from rest at a station and accelerates at a rate of 1.60 m/s2 for 14.0s. It runs at a constant speed for 70.0 s and then slows down at a rate of -3.50 m/s2 until it stops at the next station. a) Sketch a position vs. time graph for this problem. b) Sketch...
*June 4, 2012 by cody*

**Physics**

1. A small plane can travel at 200 km/h in still air. If a 50.0 km/h wind is coming from the east, determine the ground velocity of the plane if the pilot keeps the plane pointed [N]. 2. A pilot is flying from City A to City B which is 300 km [NW]. If the plane will encounter ...
*April 24, 2014 by Corey Brown*

**Physics help?**

Nitrogen gas molecules, which have mass 4.65×10−26 kg, are striking a vertical container wall at a horizontal velocity of positive 440 m/s. 5.00×1021 molecules strike the wall each second. Assume the collisions are perfectly elastic, so each particle rebounds off the ...
*June 2, 2012 by Megan*

**physic**

Hi! Question:A ball is tossed from an upper-story window of a building.The ball is given an initial velocity of 7.80m/s at an angle of 21.0 degrees below the horizontal.It strikes the ground 3.00s later. A.How far horizontally from the base of the building does the ball strik ...
*September 30, 2009 by Chan*

**physics**

A rocket is fired straight up and accelerates upward at 24 m/s2 for 12 seconds. The rocket then runs out of fuel and coasts. Ignore any air resistance effects and use -9.8 m/s2 for the local acceleration due to gravity. a) What is the rocket’s maximum altitude? b) How long is ...
*September 28, 2011 by help*

**Physics please check**

1) Two identical automobiles have the same speed, one traveling east and one traveling west. Do these cars have the same momentum? Explain. No. Same car, same mass, same speed, but different velocity. correct. Momentum is a vector.
*April 3, 2007 by Mary*

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