Tuesday

July 29, 2014

July 29, 2014

Number of results: 12,191

**Physics**

A hot-air balloon is accelerating upward under the influence of two forces, its weight and the buoyant force. For simplicity, consider the weight to be only that of the hot air within the balloon, thus ignoring the balloon fabric and the basket. The hot air inside the balloon ...
*June 23, 2013 by Name*

**Physics**

A hot-air balloon is accelerating upward under the influence of two forces, its weight and the buoyant force. For simplicity, consider the weight to be only that of the hot air within the balloon, thus ignoring the balloon fabric and the basket. The hot air inside the balloon ...
*June 23, 2013 by Name*

**physics**

1.A hot air balloon is rising upwards at a constant velocity of 5m.s when the balloon is 100m above the ground, a sandbag is dropped from it. 1.1 what is the magnitude of the acceleration of:a)The hot-air balloon while the sandbag is in it.b)The sandbag the moment is dropped ...
*March 17, 2010 by Tebogo*

**Physics**

A hot-air balloon is rising upward with a constant speed of 2.21 m/s. When the balloon is 2.25 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*January 25, 2007 by Jena*

**physics**

A hot-air balloon is rising upward with a constant speed of 2.95 m/s. When the balloon is 3.30 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*September 14, 2009 by RE*

**Physics**

A hot-air balloon is rising upward with a constant speed of 2.83 m/s. When the balloon is 8.64 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*October 14, 2011 by Nsilo*

**Physics**

A hot-air balloon is rising upward with a constant speed of 2.50 m/s. When the balloon is 3.00 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*February 1, 2012 by James*

**physics**

A hot-air balloon is rising upward with a constant speed of 2.50 m/s. When the balloon is 3.00 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*March 9, 2012 by rachel*

**physics **

A hot-air balloon is rising upward with a constant speed of 2.22 m/s. When the balloon is 7.74 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*September 6, 2012 by colby*

**physics**

A hot-air balloon is rising upward with a constant speed of 3.06 m/s. When the balloon is 9.31 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*September 9, 2012 by ray*

**physics**

A hot-air balloon is rising upward with a constant speed of 3.93 m/s. When the balloon is 4.91 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*June 14, 2013 by Anonymous*

**physics**

A hot-air balloon is rising upward with a constant speed of 2.00 m/s. When the balloon is 3.37 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*June 17, 2013 by louis aaaa*

**Phyics**

A hot-air balloon is rising upward with a constant speed of 4.00 m/s. When the balloon is 4.77 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*September 25, 2013 by Tracy*

**Phyics**

A hot-air balloon is rising upward with a constant speed of 4.00 m/s. When the balloon is 4.77 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*October 20, 2013 by Johnny*

**Physics**

A hot-air balloon is rising upward with a constant speed of 2.20 m/s. When the balloon is 2.50 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
*January 24, 2014 by Sam*

**Physics**

A hot-air balloon is rising upward with a constant speed of 2.27 m/s. When the balloon is 9.14 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground? I solve for the quadratic and ...
*September 10, 2013 by Shawn*

**Physics**

A hot-air balloon is rising upwards at a constant velocity of 5m.s . When the balloon is 100m above the ground , a sandbag is dropped from it. Will the velocity of the hot-air balloon increase , decrease or remain the same immediately after the sandbag has been released ? ...
*April 25, 2013 by Lesiba*

**physics**

a hot air balloon rise above the ground, accelerating upwards at a rate of 2 m/s^2. The total mass of the hot air balloon and it occupants is 400kg. the density of the air is 1.3 kg/m^3. a) Determine the volume if the hot air balloon. b) if this acceleration is maintained for ...
*September 1, 2010 by Mikey*

**Physical science**

On a perfect day, you are hovering at low altitude in a hot-air balloon, accelerated neither upward or downward. The total wieght of the balloon, including its load and the hot air in it is 20,000N. Show that the volume of the displaced air is 1700 m3 (Hint:Buoyancy in a Gas)
*February 24, 2008 by Rachel*

**Hot-air balloon**

A hot-air balloon is 180 ft above the ground when a motorcycle passes directly beneath it (travelling in a straight line on a horizontal road) going at a constant speed of 60 ft/s. If the balloon is rising vertically at a rate of 15 ft/s, what is the rate of change of the ...
*March 15, 2011 by Jake*

**physics**

On a perfect fall day, you are hovering at low altitude in a hot-air balloon, accelerated neither upward nor downward. The total weight of the balloon, including its load and the hot air in it, is 24000 N. Find the weight of the displaced air. Find the volume of the displaced ...
*March 28, 2012 by Kristie*

**physics**

On a perfect fall day, you are hovering at low altitude in a hot-air balloon, accelerated neither upward nor downward. The total weight of the balloon, including its load and the hot air in it, is 24000 N. Find the weight of the displaced air. Find the volume of the displaced ...
*March 29, 2012 by Jim*

**PHYSICS**

Several people are riding in a hot-air balloon. The combined mass of the people and balloon is 308 kg. The balloon is motionless in the air, because the downward-acting weight of the people and balloon is balanced by an upward-acting 'buoyant' force. If the buoyant force ...
*September 23, 2010 by Sarah*

**physics**

Several people are riding in a hot-air balloon. The combined mass of the people and balloon is 310 kg. The balloon is motionless in the air, because the downward-acting weight of the people and balloon is balanced by an upward-acting “buoyant” force. If the buoyant force ...
*January 4, 2011 by Anonymous*

**physics**

Several people are riding in a hot-air balloon. The combined mass of the people and balloon is 328 kg. The balloon is motionless in the air, because the downward-acting weight of the people and balloon is balanced by an upward-acting 'buoyant' force. If the buoyant force ...
*October 4, 2012 by Donald*

**physics**

Several people are riding in a hot-air balloon. The combined mass of the people and balloon is 284 kg. The balloon is motionless in the air, because the downward-acting weight of the people and balloon is balanced by an upward-acting 'buoyant' force. If the buoyant force ...
*September 26, 2013 by Donna*

**physics**

On a perfect fall day, you are hovering at low altitude in a hot-air balloon, accelerated neither upward nor downward. The total weight of the balloon, including its load and the hot air in it, is 24000 N. Find the weight of the displaced air. I got the weight=2.4×10^4 N but ...
*March 31, 2012 by Kristie*

**physics**

On a perfect fall day, you are hovering at low altitude in a hot-air balloon, accelerated neither upward nor downward. The total weight of the balloon, including its load and the hot air in it, is 24000 N. Find the weight of the displaced air. I got the weight=2.4×10^4 N but ...
*April 1, 2012 by Kristie*

**physics**

On a perfect fall day, you are hovering at low altitude in a hot-air balloon, accelerated neither upward nor downward. The total weight of the balloon, including its load and the hot air in it, is 24000 N. Find the weight of the displaced air. !!I got this: it is 2.4×10^4 N I...
*April 3, 2012 by christy*

**Physics**

A hot air balloon is rising at a constant velocity of 13.3 m/s. When the balloon is at a height of 15 m, a heavy object is dropped overboard. IF air resistance on the object is neglected, how long does it take for it to reach the ground?
*October 4, 2011 by Jessica*

**calculus**

A hot air balloon rising straight up form a level field is tracked by a range finder 500ft from the liftoff point. At the moment the range finders elevation ange is pi/4, the angle is increasing at 0.14 rad/min. How fast is the balloon rising at that moment?
*October 17, 2010 by Denzel*

**Physics(thank you for the help)**

A hot-air balloon is rising upward with a constant speed of 2.45 m/s. When the balloon is 3.22 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground? I know that average speed ...
*May 27, 2012 by Hannah*

**Physics**

Hot air balloons float in the air because of the difference in density between cold and hot air. In this problem, you will estimate the minimum temperature the gas inside the balloon needs to be, for it to take off. To do this, use the following variables and make these ...
*July 13, 2011 by Jenny*

**calculus**

A hot air balloon rising vertically is tracked by an observer located 4 miles from the lift-off point. At a certain moment, the angle between the observer's line-of-sight and the horizontal is \frac{\pi}{3} , and it is changing at a rate of 0.1 rad/min. How fast is the balloon...
*March 7, 2014 by MEMO*

**physics**

A balloonist, riding in the basket of a hot air balloon that is rising vertically with a constant velocity of 10.1 m/s, releases a sandbag when the balloon is 43.4 m above the ground. Neglecting air resistance, what is the bag's speed when it hits the ground? Assume g = 9.80 m...
*March 3, 2010 by Jake*

**Physics**

A balloonist, riding in the basket of a hot air balloon that is rising vertically with a constant velocity of 9.5 m/s, releases a sandbag when the balloon is 44.3 m above the ground. Neglecting air resistance, what is the bag's speed when it hits the ground? Assume g = 9.80 m/...
*September 4, 2012 by Sherry*

**chemistry**

hot-air balloon is filled with air at a volume of 3.64 x 10^3 m^3 at 745 torr at 39C. the air in balloon is heated to 60C, causing balloon to expand to a volume of 4.50x 10^3 m^3. what is the ratio of the number of moles of the air in heated balloon to original number of moles...
*November 15, 2007 by mel*

**physics**

A hot-air balloon plus cargo has a mass of 1740 {\rm kg} and a volume of 12030 {\rm m^3}. The balloon is floating at a constant height of 6.25 {\rm m} above the ground. What is the density of the hot air in the balloon?
*January 26, 2012 by Dave*

**physics**

A hot-air balloon plus cargo has a mass of 1740 {\rm kg} and a volume of 12030 {\rm m^3}. The balloon is floating at a constant height of 6.25 {\rm m} above the ground. What is the density of the hot air in the balloon?
*January 26, 2012 by Dave*

**Physics**

A coin is dropped from a hot-air balloon that is 325 m above the ground and rising at 12.5 m/s upward. For this problem use a coordinate system in which up is positive. Find the maximum height reached for the coin in meters
*February 15, 2014 by Anonymous*

**physics**

A helium balloon has a mass of 0.022 kg, which includes both the helium and the balloon itself. On this balloon, there is 0.290 N of buoyant force pushing the balloon upward. If I let go of the balloon, find the balloon's acceleration rate in the upward direction. If we ...
*May 12, 2013 by Nick*

**Math**

A hot air balloon is rising vertically. From a point on level ground 125 ft. from a point on ground level directly under the balloon the angle of elevation of the balloon changes from 19.2 to 31.7. How far does the balloon rise during this period? Draw a diagram when answering...
*November 29, 2012 by Thalia*

**physics31**

1.A man in a hot-air balloon drops an apple at a height of 150m. If the balloon is rising at 15 m/s, find the highest point reached by the apple.
*October 1, 2011 by cedric*

**Calculus**

A hot air balloon rising vertically is tracked by an observer located 3 miles from the lift-off point. At a certain moment, the angle between the observer's line-of-sight and the horizontal is pi/5 , and it is changing at a rate of 0.1 rad/min. How fast is the balloon rising ...
*October 30, 2011 by Reonea*

**Please Help!!!!!!**

a hot air balloon is rising vertically 10 ft/sec while the wind is blowing horizontally 5ft/sec. Find the speed of the balloon and the angle x that it makes with the horizontal. I know that the speed of the balloon is the square root of (10)^2 + (5)^2, but I was wondering if ...
*November 10, 2011 by Ashley*

**physics**

A hot-air balloon of mass 200 kg is descending vertically with downward acceleration of magnitude 1.2 m/s2. How much mass (ballast) must be thrown out to give the balloon an upward acceleration of magnitude 1.2 m/s2 (same magnitude but opposite direction)? Assume that the ...
*March 2, 2011 by karim*

**physics**

A hot-air balloon of mass 200 kg is descending vertically with downward acceleration of magnitude 1.2 m/s2. How much mass (ballast) must be thrown out to give the balloon an upward acceleration of magnitude 1.2 m/s2 (same magnitude but opposite direction)? Assume that the ...
*March 2, 2011 by karim*

**physics**

A)You are in a hot air balloon (yes, another balloon problem!) rising from the ground at a constant velocity of 2.50 m/s upward. To celebrate the takeoff, you open a bottle of champagne, expelling the cork with a horizontal velocity of 5.70 m/s relative to the balloon. When ...
*January 31, 2014 by Eleni*

**Math, Please Help!!!**

a hot air balloon is rising vertically 10 ft/sec while the wind is blowing horizontally 5ft/sec. Find the speed of the balloon and the angle x that it makes with the horizontal. I know that the speed of the balloon is the square root of (10)^2 + (5)^2, but I was wondering if ...
*November 10, 2011 by Jenny Star*

**Math, Please Help!!!**

a hot air balloon is rising vertically 10 ft/sec while the wind is blowing horizontally 5ft/sec. Find the speed of the balloon and the angle x that it makes with the horizontal. I know that the speed of the balloon is the square root of (10)^2 + (5)^2, but I was wondering if ...
*November 10, 2011 by BOB*

**science**

You are a maker of hot air balloons and wish to construct a balloon that will lift you and a friend to places unknown. Your standard balloon design is a perfectly spherical, nylon fabric balloon with a small hole on the bottom for the burner that heats the air. Nylon starts to...
*April 11, 2013 by Sahil*

**Chemistry**

The total mass that can be lifted by a balloon is given by the difference between the mass of air displaced by the balloon and the mass of the gas inside the balloon. Consider a hot air balloon that approximates a sphere 5.00 m in diameter and contains air heated to 65 C. The ...
*December 14, 2012 by Savannah*

**Chemistry**

The total mass that can be lifted by a balloon is given by the difference between the mass of air displaced by the balloon and the mass of the gas inside the balloon. Consider a hot air balloon that approximates a sphere 5.00 m in diameter and contains air heated to 65 C. The ...
*December 16, 2012 by Savannah*

**calculus**

a hot-air balloon rising srtaight up from level field is tracked by a range finder 5000 feet from the liftoff point. At the moment the range finder's elevation angle is 45 degrees (pie/4 radians), the angle is increasing at the rate of 0.14 radians per minute. how fast is the ...
*December 5, 2009 by marlyn*

**Physics**

A hot air balloon is traveling vertically upward at a constant speed of 3.9 m/s. When it is 20 m above the ground, a package is released from the balloon. After it is released, for how long is the package in the air? The acceleration of gravity is 9.8 m/s
*October 10, 2011 by Ana *

**Calculus **

A hot-air balloon is 180 ft above the ground when a motorcycle passes directly beneath it (travelling in a straight line on a horizontal road) going at a constant speed of 60 ft/s. If the balloon is rising vertically at a rate of 15 ft/s, what is the rate of change of the ...
*March 15, 2011 by Jake*

**Physics :(( help please TT**

You are a maker of hot air balloons and wish to construct a balloon that will lift you and a friend to places unknown. Your standard balloon design is a perfectly spherical, nylon fabric balloon with a small hole on the bottom for the burner that heats the air. Nylon starts to...
*April 12, 2013 by Ian*

**Algebra**

in that equation I have to solve for x. 5. x^3 + 2x^2 - 9x = 18 in this word problem i have to solve my factoring. 8. Suppose the altitude of a rising hot-air balloon is given by h = 0.04 t2 + 2t, where “t” is the time in seconds after the balloon leaves the ground. How long ...
*March 9, 2009 by Jordan*

**Physics HELP**

A hot air balloon is 2.5m above the ground rising at 2m/s. A camera is thrown from the ground at 13m/s. At what height do the camer and balloon meet. Need to know the correct formulas and how to insert the data. Stuck on this question for homework.
*September 18, 2011 by john*

**physics**

A hot air balloon is traveling vertically upward at a constant speed of 3.9 m/s. When it is 10 m above the ground, a package is released from the balloon. After it is released, for how long is the package in the air? The acceleration of gravity is 9.8 m/s 2 . Answer in units of
*November 22, 2011 by Anonymous*

**geometry**

Hot air balloons require large amounts of both hot air and fabric material. A hot air balloon is spherical with a diameter of 25 feet . a. Does finding the surface area help you determine the amount of the hot air or the fabric material? Explain
*March 3, 2012 by kim*

**calculus**

A hot-air balloon is 150 feet above the ground when a motorcycle passes directly beneath it (traveling in a straight line on a horizontal road). The motorcycle is traveling at 40 mph. If the balloon is rising vertically at a rate of 10 ft/sec, what is the rate of change of the...
*November 13, 2012 by Leigh*

**physics**

A hot air balloon has just lifted off and is rising at the constant rate of 1.8 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 11.2 m/s. If the passenger is 2.5 m ...
*September 16, 2010 by jack*

**physics**

There are many ropes keeping a hot air balloon from floating away before a balloon race. One of these ropes is fixed to the ground at a 45° angle. Another is fixed to the ground at a 30° angle. If the hot air balloon is 18 feet off the ground, what is the distance between the ...
*December 17, 2011 by chukwuyem ekufu*

**Physics**

A hot air balloon has just lifted off and is rising at the constant rate of 2.2 m/s. Suddenly one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 11.6 m/s. If the passenger is 2.5 m ...
*September 16, 2008 by nick*

**physics**

A hot-air balloon has just lifted off and is rising at the constant rate of 1.51 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 13.00 m/s. If the passenger is 2.68...
*September 8, 2012 by Nathan*

**physics**

A hot-air balloon has just lifted off and is rising at the constant rate of 1.51 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 13.00 m/s. If the passenger is 2.68...
*September 8, 2012 by Nathan*

**physics**

A)You are in a hot air balloon rising from the ground at a constant velocity of 2.50 m/s upward. To celebrate the takeoff, you open a bottle of champagne, expelling the cork with a horizontal velocity of 5.70 m/s relative to the balloon. When opened, the bottle is 6.40 m above...
*February 1, 2014 by Eleni*

**physics**

A hot air balloon is traveling vertically upward at a constant speed of 5.3 m/s. When it is 25 m above the ground, a package is released from the balloon. After it is released, for how long is the package in the air? The acceleration of gravity is 9.8 m/s^2. Answer in units of...
*September 9, 2012 by maura*

**Physics**

A hot-air balloon is rising straight up with a speed of 5.4 m/s. A ballast bag is released from rest relative to the balloon when it is 11.2 m above the ground. How much time elapses before the ballast bag hits the ground?
*September 18, 2012 by Anonymous*

**physics**

A hot-air balloon is rising straight up with a speed of 6 m/s. A ballast bag is released from rest relative to the balloon at 7 m above the ground. How much time elapses before the ballast bag hits the ground?
*January 31, 2013 by Dee*

**pre cal**

Tamara is flying in a hot air balloon. The hot air balloon is flying at an altitude of 1100 feet. The ground distance to the landing site is 1400 feet. What is Tamara's angle of depression to the landing site? What is the actual distance between the hot air balloon and the ...
*February 6, 2011 by karina*

**Physics**

A hot-air balloon is rising straight up with a speed of 5 m/s. A ballast bag is released from rest relative to the balloon when it is 8.2 m above the ground. How much time elapses before the ballast bag hits the ground? I don't get what equations or what values to use for this...
*September 10, 2010 by Jerry*

**Chemistry**

A hot air balloon is filled with 1.39 × 106 L of an ideal gas on a cool morning (11 °C). The air is heated to 105 °C. What is the volume of the air in the balloon after it is heated? Assume that none of the gas escapes from the balloon.
*October 16, 2012 by Bill*

**physics**

A typical volume of a modern hot air balloon is 2500 cubic metres, and a typical maximum temperature of the hot air is 120 degrees Celsius. Given these figures, and an outside air temperature and density of 15 \(^{\circ}C\) and 1.225 \(kg/m^3\) respectively, compute the ...
*March 27, 2014 by Nick*

**physics**

A recreational (open) hot air balloon (i.e., Pinside is approximately the same as Poutside) has a volume of 2227 m3 when fully inflated. The total weight of the balloon, basket, ballast and pilot is 1775.6 N (399 lb). How much less dense must the air in the balloon be than the...
*April 4, 2012 by katie *

**Physics**

A hot-air balloon is rising vertically at a speed of 10 m s–1. An object is released from the balloon. The graph shows how the velocity of the object varies with time from when it leaves the balloon to when it reaches the ground four seconds later. It is assumed that the air ...
*February 16, 2011 by tania*

**Chemistery**

A hot air balloon with a volume of 3.20 x 10^3 L and 120 moles of air is at a temperature of 20C. How many moles of air will the balloon contain if it expands to 4.80 x 10^3 L and the air is heated to 45C?
*March 11, 2014 by Garrett*

**physics**

A) A hot air balloon has just lifted off and is rising at the constant rate of 1.70 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 10.4 m/s. If the passenger is 3....
*January 25, 2014 by Cat*

**science**

Why does a hot air balloon begin to rise when heated air is trapped inside the balloon? Thanks so much for the help, :)~happy
*January 11, 2010 by :)~happy*

**calculus**

You are letting the air out of a hot air balloon at a steady rate. The volume of the balloon is decreasing at the rate of 10pi m^3/min when the diameter is 45 meters. At what rate is the radius of the balloon changing? I need help! How do I solve this problem? Thank you so ...
*November 18, 2007 by Anonymous*

**Chemistry**

A hot-air balloon has a volume of 4.000 x 10^5 L at 30 degrees celsius and a pressure of 748 mmHg. If the average molar mass of air is 29.0 g/mol, what is the mass of air in the balloon?
*December 9, 2011 by Dani*

**Chemistry**

A hot air balloon has a volume of 3.𝑔80 x 105 L at 42 °C and a pressure of 754 mm Hg. If the average molar mass of air is 29.0 𝑚𝑜𝑙, what is the mass of air, in grams, in the balloon?
*November 6, 2013 by Anonymous*

**pre cal**

Tamara is flying in a hot air balloon. The hot air balloons is flying at an altitude of 1100 feet. The ground distance to the landing site is 1400 feet. What is Tamara's angle of depression to the landing site? What is the actual distance between the hot air balloon and the ...
*February 8, 2011 by karina*

**physics**

The air inside a hot air balloon has an average temperature of 71.7° C. The outside air has a temperature of 11.1° C. What is the ratio of the density of air in the balloon to the density of air in the surrounding atmosphere?
*December 3, 2011 by Anonymous*

**math**

A hot air balloon was at a height of 60 feet above the ground when it began to ascend. The balloon climbed at a rate of 15 feet per minute. a) make a table that shows the height of the air balloon after climbing for 1,2,3,&4 minutes. minutes:1 2 3 4 ------------------- height:...
*December 16, 2013 by B8*

**Calculus**

t: 0 2 5 7 11 12 r'(t): 5.7 4.0 2.0 1.2 0.6 0.5 The volume of a spherical hot air balloon expands as the air inside the balloon is heated. The radius of the balloon in feet is modeled by a twice-differentiable function of r of time t, where t is measured in minutes. For 0<t...
*November 25, 2008 by Craig*

**8th grade science**

If you see that a hot-air balloon is rising above the top of a hill, what is the top of the hill called?
*May 1, 2014 by skiler*

**science**

If you see that a hot-air balloon is rising above the top of a hill, what is the top of the hill called?
*April 17, 2014 by isaiah*

**Physics**

The density of air near the earth's surface is 1.29 kg?m^3. If a helium balloon with a mass of 1 kg floats in air without rising or falling,what is the minimum volume of helium in the balloon? (presume that the mass of the material making up the balloon is negligible). I am ...
*February 16, 2012 by Jonathon*

**physical science**

A hot air balloon is rising upwards at a constant velocity of 5 m/s . When the balloon is 60 m above the ground , a sand bag is released from it and allowed to free fall . Ignore the effect of air resistance and assume that the balloon continues to move with the same constant ...
*March 21, 2013 by Sandile*

**Physics**

You hold an inflated balloon over a hot air vent in your house and watch it slowly expand. You then remove it and let it cool back to room temperature. During the expansion, which was larger: the heat added to the balloon or the work done by the air inside? explain. (assume ...
*January 25, 2013 by Jasmine*

**Physics conceptual**

You hold an inflated balloon over a hot air vent in your house and watch it slowly expand. You then remove it and let it cool back to room temperature. During the expansion, which was larger: the heat added to the balloon or the work done by the air inside? explain. (assume ...
*January 25, 2013 by Jasmine*

**math**

a hot-air balloon is seen in the sky simultaneously by two observers standing a t two different points on the ground. (the 2 people are facing each other and the balloon is in between them in the air.)they are 1.75 miles apart on level ground. The angles of elevation are 33 ...
*March 28, 2011 by lulu*

**math**

a hot-air balloon is seen in the sky simultaneously by two observers standing a t two different points on the ground. (the 2 people are facing each other and the balloon is in between them in the air.)they are 1.75 miles apart on level ground. The angles of elevation are 33 ...
*March 28, 2011 by lulu*

**physics**

A 4.92E+2 kg hot-air balloon takes off from rest at the surface of the earth. The nonconservative wind and lift forces take the balloon up, doing +9.81E+4 J of work on the balloon in the process. At what height above the surface of the earth does the balloon have a speed of 7....
*May 9, 2010 by Fallon*

**physics**

a hot-air balloon having initial velocity vi as it ascends. Then, a water balloon is dropped from the basket when it is 135 meters high and would hit the ground after 9.00 seconds. a) find the velocity of the hot-air balloon upon release of the water balloon. The person in the...
*October 2, 2012 by lib*

**chemistry**

Use the kinetic molecular theory of gases to explain each of the following: a. a container of nonstick cooking spray explodes when thrown into a fire. b. the air in a hot-air balloon is heated to make the balloon rise.
*November 10, 2012 by Boo Boo*

**math**

a hot air balloon is tied to the ground with 200 ft. of rope. The wind is pushing the balloon to make a 23 degree angle with the ground. What is the real height of the balloon?
*December 10, 2012 by ss*

**UNM**

In an air-conditioned room at 19.0C , a spherical balloon had the diameter of 50.0cm . When taken outside on a hot summer day, the balloon expanded to 51.0cm in diameter. What was the temperature outside? Assume that the balloon is a perfect sphere and that the pressure and ...
*October 3, 2009 by Monica *

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