Tuesday

May 24, 2016
Number of results: 1,294

**Physics**

After rubbing a balloon against someone's hair, a balloon has accumulated a static electric charge. The air inside the balloon has the same density as the air outside of the balloon, and the balloon itself weighs 1.41mN. How many free electrons are there on the surface of the ...
*January 30, 2012 by Anonymous*

**Chemistry**

You have two gas-filled balloons, one containing He and the other containing H2. The H2 balloon is twice the size of the He balloon. The pressure of gas in the H2 balloon is 1 atm, and that in the He balloon is 2 atm. The H2 balloon is outside in the snow (−5 °C), and ...
*March 30, 2007 by Luis*

**Chemistry **

You have two gas-filled balloons, one containing He and the other H2. The H2 balloon is twice the size of the He balloon (let the He balloon have a volume of 1 -L and the H2 balloon. a volume of 2 L). The pressure of gas in the H2 balloon is 1 atm while that in the He balloon ...
*February 19, 2012 by Bria*

**Physics**

A weather balloon is released at an altitude of 500m. The force of gravity on the balloon is 21.1n. The lift force provided by the atmosphere is 18.7n. Which of the following is true about the balloon? a. The balloon rises at constant velocity. b. the net force on the balloon...
*May 6, 2015 by Katie*

**trigonometry**

a captive balloon is connected to a ground station A by a cable of length 842 ft inclined 65 degrees to the horizontal. In a vertical plane with the balloon and its station and on the opposite side of the balloon from A, a target B was sighted from the balloon on a level with ...
*August 26, 2014 by rhinechilde*

**trigonometry**

a captive balloon is connected to a ground station A by a cable of length 842 ft inclined 65 degrees to the horizontal. In a vertical plane with the balloon and its station and on the opposite side of the balloon from A, a target B was sighted from the balloon on a level with ...
*August 27, 2014 by rhinechilde*

**math**

a captive balloon is connected to a ground station A by a cable of length 842 ft inclined 65 degrees to the horizontal. In a vertical plane with the balloon and its station and on the opposite side of the balloon from A, a target B was sighted from the balloon on a level with ...
*August 27, 2014 by rhinechilde*

**Physics**

A 5.00 x 102 kg hot air balloon takes off from rest at the surface of the earth. The buoyant force lifts the balloon straight up, performing 9.70 x 104 J of work on the balloon. At the instant the balloon's upward speed is 4.08 m/s, the balloon will be ____ m above the surface...
*November 18, 2014 by Help*

**physics**

A large balloon of mass 237 kg is filled with helium gas until its volume is 318 m3. Assume the density of air is 1.29 kg/m3 and the density of helium is 0.179 kg/m3. (b) Calculate the buoyant force acting on the balloon.________N (c) Find the net force on the balloon and ...
*November 7, 2012 by Amanda*

**PHYSICS**

A large balloon of mass 237 kg is filled with helium gas until its volume is 318 m3. Assume the density of air is 1.29 kg/m3 and the density of helium is 0.179 kg/m3. (b) Calculate the buoyant force acting on the balloon. ________N (c) Find the net force on the balloon and ...
*November 8, 2012 by Amy*

**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*

**Math**

A water balloon is shot into the air so that its height h, in metres, after t seconds is h = —4.9t^2 + 27t + 2.4 a)How high is the balloon after 1 s? b)For how long is the balloon more than 30 m high? c)What is the maximum height reached by the balloon? d)When will the balloon...
*January 22, 2009 by gagan*

**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*

**Algebra-Trig Please Help ASAP**

A balloon isin the vertical plane of two consecutive milestones of a road. The angles of depression of the stones as viewed from the balloon are 15 degrees and 17 degrees. Find the height of the balloon if (a) the stones are on opposite sides of the balloon, (b) the stones are...
*February 15, 2012 by Candy*

**Physics**

An empty rubber balloon has a mass of 0.012kg. the balloon is filled with helium at 0 degrees celcius, 1 atm pressure, and a density of 0.179 kg/m3. the filled balloon has a radius of 0.5 m. a)what is the magnitude of the buoyant force acting on the balloon? b)what is the ...
*March 4, 2010 by Taylor*

**physics**

In a water balloon toss a contestant throws her balloon with a speed of 4.84 m/s at an angle of 16.5 degrees above the horizontal. Find the maximum height, the time of flight and the range of the balloon assuming her partner catches the balloon at the same height at which it ...
*February 6, 2012 by becky*

**Physics**

An empty rubber balloon has a mass of 0.0120 kg. The balloon is filled with helium at 0 degrees celsuis, 1 atm pressure, and a density of 0.179kg/m^3. The filled balloon has a radius of .5m a)What is the magnitude of the net force acting on the balloon? b) What is the ...
*May 18, 2016 by Sara Draz*

**Chemistry**

A hot air balloon is filled with hot air and the hot air forces the volume of the balloon to expand until the density of the gas in the balloon is less than the density of the outside air. The volume must be 20% larger than the balloon would be at STP in order for the balloon ...
*April 25, 2016 by Chem*

**chemistry**

A hot air balloon is filled with hot air and the hot air forces the volume of the balloon to expand until the density of the gas in the balloon is less than the density of the outside air. The volume must be 20% larger than the balloon would be at STP in order for the balloon ...
*April 25, 2016 by jenna*

**Physics**

A hot air balloon of radius 12 meters has been heated so that the air inside has a density of 1.05 kg/m^3. What can the total load of the balloon be (mass of balloon itself plus cargo) if you need the balloon to accelerate into the air with an acceleration of 4 m/s^2?
*January 2, 2015 by Christina*

**Geography **

Hot air balloon A is raising upward at a rate of 10.0 m/s. A passenger aboard balloon A observers balloon B going down at a relative rate of 12.5 m/s. What is the velocity of balloon B relative to the group?
*January 19, 2016 by Maricela*

**Math**

a balloon is rising vertically at the rate of 2 m/s. an observer is standing on the ground 100m away from a point directly below the balloon. at what rate is the distance between the observer and the balloon changing when the balloon is 160m high?
*September 13, 2012 by Gladys Garcia*

**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*

**physics**

an empty rubber balloon has mass 0.0120kg, the balloon is filled with helium of density 0.181 kg/m^3. the balloon is spherical w/ radius 0.500m. if the balloon is ties to a vertical string, what is thw tension in the string? density of air 1.29 kg/m^3
*December 15, 2012 by Helen*

**Physics**

A water balloon is thrown horizontally at a speed of 2.00 m/s from a roof of a building that is 6.00 m above ground. At the same instant the balloon is released a second balloon is thrown straight down at 2.00 m/s from the same height. Determine which balloon hits the ground ...
*September 25, 2012 by Lisa K.*

** balloon**

if an inflated balloon is placed in the freezer as the temperature of the gas of the balloon decrease the speed of the particles will do what
*September 11, 2011 by Anonymous*

**geometry**

you are at a parade looking up at a large balloon floating directly above the street. you are 60 feet away from a point on the street directly Beneath the balloon. to see the top of the balloon your angle of elevation is 53°. to see the bottom of the balloon your angle of ...
*April 21, 2016 by Susie *

**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*

**Chemistry (balloon)**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.3 kg m-3. Under these conditions the total surface area of the balloon is 0.33 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*December 15, 2012 by T*

**math**

A water balloon is shot into the air so that its height h, in metres, after t seconds is h = —4.9t^2 + 27t + 2.4 a)How high is the balloon after 1 s? b)For how long is the balloon more than 30 m high? c)What is the maximum height reached by the balloon? d)When will the balloon...
*January 23, 2009 by gagan*

**physics**

A water balloon is dropped from the top of a building. Assume the balloon does not break when it strikes the ground. If the water balloon falls a distance of 21m, what is the maximum temperature rise of the water balloon due to it being dropped?
*October 12, 2010 by Maria*

**physics**

A water balloon dropped from a dorm window does not break on impact. From what height would you need to drop the balloon to double the speed of the balloon?
*February 25, 2011 by brittany*

**AP Chemistry**

The buoyant force on a balloon is equal to the mass of air it displaces. The gravitational force on the balloon is equal to the sum of the masses of the balloon, the gas it contains, and the balloonist. If the balloon and balloonist together weight 175 kg, what would the ...
*October 11, 2010 by Emma*

**Physical Science**

A water balloon dropped from a dorm window does not break on impact. From what height would you need to drop the balloon to double the speed of the balloon?
*February 25, 2011 by Miguel*

**Math**

The hot air balloon operator allows the balloon to descend at a rate of 23 ft per minute. If they have been descending for 6 minutes how far has the balloon descended?
*December 6, 2015 by Emma*

**physics**

An empty rubber balloon has a mass of 0.0100 kg. The balloon is filled with helium at a density of 0.181 kg/m3. At this density the balloon is spherical with a radius of 0.300 m. If the filled balloon is fastened to a vertical line, what is the tension in the line?
*December 20, 2010 by april*

**PHYSICS PLEASE HELP**

A large balloon of mass 237 kg is filled with helium gas until its volume is 318 m3. Assume the density of air is 1.29 kg/m3 and the density of helium is 0.179 kg/m3. (b) Calculate the buoyant force acting on the balloon. ____________N (c) Find the net force on the balloon and...
*November 8, 2012 by AMY*

**Physics**

Hey, it's me again, Can someone help me with this question? A water balloon is dropped from the top of a building. Assume the balloon does not break when it strikes the ground. If the water balloon falls a distance of 21m, what is the maximum temperature rise of the water ...
*June 28, 2011 by Josh*

**Physics**

A hot air balloon is hovering at an altitude of 6000 meters. The pilot decides that it is time to descend and turns off the balloon's burners. Once the balloon reaches the ground, the gas inside the balloon occupies 980 m^3 and is at atmospheric pressure. If the pressure of ...
*February 18, 2012 by GRISSELL*

**science-biology**

In lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell". The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the folloing ...
*November 19, 2010 by Tracee*

**chem**

I am filing out a study guide and needed coaching on some question. thank you 0.765 g of He is placed in a balloon at 1.15 atm. The balloon expands to volume of 5.00 L. What is the temperature of the balloon? a,3.45 K b,91.6 K c,93.4 K d,366 K
*November 17, 2015 by david*

**Physics**

In this problem, your task is to analyze a lead balloon. The balloon in question is a hollow sphere of diameter of 20.0 m, constructed from a lead foil 0.25 mm thick and filled with helium gas. Below the balloon, a passenger basket is suspended. The mass of the passenger ...
*June 15, 2012 by Rob*

**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*

**math**

A design on a balloon is 6 cm wide when the balloon holds 44 cm to the third power of air. How much must the balloon hold for the design to be 24 cm wide? Since the "width" increases by a factor of 4, the volume will increase by a factor of 4^3 = 64, even if the balloon is not...
*November 25, 2006 by Susie*

**ph 411**

a baloon is rising at a constant speed of 10m/s. when the balloon is 1400 m above the ground a bullet is fired from a gun at ground level straight up at the balloon with a speed of 200 m/s. a) does the bullet hit the balloon? b)if so how high above the ground does it hit the ...
*June 16, 2013 by adesh*

**Physics**

A balloon is filled with 3.4L of helium gas at 10.C. The temperature of the balloon increases to 50. C after being placed in a car on a sunny day. What is the final volume of the balloon? (assume that B is the saem as for air)
*December 8, 2011 by Dorrito*

**Urgent Help needed in PHYSICS!**

A spherical balloon is inflated to a diameter of 20.0 cm. Assume that the gas in the balloon is of atmospheric pressure (101.3 kPa) and is at a temperature of 20.0 ˇăC. It is then taken by a diver 15.0 m under the sea. The temperature of the seawater at this depth is 16.0 ˇăC...
*April 9, 2013 by tommy*

**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 *

**math**

bystander at the Pegasus Parade, is lying on his back and observing a large balloon of a cartoon character, floating directly above Broadway Street. He is located 32 feet from a point on the street directly beneath the balloon. To see the top of the balloon, he looks up at an ...
*May 22, 2014 by luis*

**Math**

A spherical balloon expands uniformly as it is inflated. The radius of the balloon in r meters at time t seconds. Find the radius, the volume, and the surface area of the balloon when the rates of increase of the surface area of the balloon and the radius are numerically equal
*November 30, 2015 by Daniel *

**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*

**Chemistry**

2 moles of helium (He) are pumped from a gas canister into a weather balloon. The balloon at this point has a volume V1. 1 mole of nitrogen gas (N2) is added at the same temperature and pressure. The volume of the balloon changes to V2. How will the new volume of the balloon ...
*April 17, 2013 by Colin*

**physics**

A child loses his balloon, which rises slowly into the sky. a) If the balloon is 21.5 cm in diameter when the child loses it, what is its diameter at an altitude of 1150 m? Assume that the balloon is very flexible and so surface tension can be neglected. b) And what is the ...
*March 21, 2012 by maria*

**Chemistry**

The buoyant force on a balloon is equal to the mass of air it displaces. The gravitational force on the balloon is equal to the sum of the masses of the balloon, the gas it contains, and the balloonist. If the balloon and balloonist together weight 175 kg, what would the ...
*October 11, 2010 by Emma*

**Physics-Help-I'm Stuck**

If a balloon is made of Mylar(alumized plastic) instead of rubber, would it stick to a wall if you rubbed the balloon against a wool sweater? If a charged balloon is held a distance "d" above some paper bits they start to move. If the balloon is moved half as close, by how ...
*April 5, 2011 by Ellie*

**Physics PLEASE help!**

I REALLY NEED HELP WITH THIS!!!!! In this problem, your task is to analyze a lead balloon. The balloon in question is a hollow sphere of diameter of 20.0 m, constructed from a lead foil 0.25 mm thick and filled with helium gas. Below the balloon, a passenger basket is ...
*June 16, 2012 by Eric*

**AP Chemistry**

The buoyant force on a balloon is equal to the mass of air it displaces. The gravitational force on the balloon is equal to the sum of the masses of the balloon, the gas it contains, and the balloonist. If the balloon and balloonist together weight 175 kg, what would the ...
*October 12, 2010 by Em*

**Chem**

A particular balloon is designed by its manufacturer to be inflated tom a volume of no more than 2.5 L. If the balloon is filled with 2.0 L of helium at sea level, is released, and rises to an altitude at which the atmospheric pressure is only 500. mm Hg, will the balloon burst?
*January 19, 2011 by Someone*

**chemistry**

A weather balloon is inflated to a volume of 27.0 at a pressure of 730 and a temperature of 31.3. The balloon rises in the atmosphere to an altitude, where the pressure is 365 and the temperature is -14.6. Assuming the balloon can freely expand, calculate the volume of the ...
*October 12, 2008 by Lili*

**AP Physics B**

An empty rubber balloon has a mass of 0.01 kg . The balloon is ﬁlled with helium at a density of 0.181 kg/m3 . At this density the balloon has a radius of 0.493 m . If the ﬁlled balloon is fastened to a vertical line, what is the tension in the line? The ...
*January 15, 2013 by Clark*

**Math**

A hot air balloon is observed from two points A and B on the ground A and B are 800 feet apart the balloon is east of both points the angle of elevation from A to the balloon is 37 degrees and the angle of elevation from B is 65 degrees what is the distance from point A to the...
*January 20, 2013 by Adreeanna*

**chem**

A very flexible helium-filled balloon is released from the ground into the air at 20degree C The initial volume of the balloon is 5.00L , and the pressure is 760mmHg. . The balloon ascends to an altitude of 20Km , where the pressure is 76.0mmHg and the temperature is 50degree ...
*November 1, 2012 by chemdummy*

**chem**

A very flexible helium-filled balloon is released from the ground into the air at 20degree C The initial volume of the balloon is 5.00L , and the pressure is 760mmHg. . The balloon ascends to an altitude of 20Km , where the pressure is 76.0mmHg and the temperature is -50degree...
*November 1, 2012 by chemdummy*

**Gas Laws**

What equation would I use to solve this problem: The volume of a balloon is 3.78 L at 22.8°C. The balloon is heated to 42.4°C. Calculate the new volume of the balloon.
*November 13, 2012 by Parkin*

**Chemistry**

Adding helium to a balloon increased its volume from 360.9 mL to 3.532 L. If the final number of moles of helium in the balloon is 22.3 mol, what was the initial number of moles of helium in the balloon? Assume the balloon contained only helium initially.
*December 10, 2014 by wendy*

**physic**

an empty rubber balloon has 0.0120 kg it filled of helium. the density of helium is 0.179 kg/m^3 of and the radius of the balloon is 0.500 what is the buoyant force over the balloon
*December 5, 2015 by Sue*

**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*

**Chemistry**

A hot air balloon is filled with hot air and the hot air forces the volume of the balloon to expand until the density of the gas in the balloon is less than the density of the outside air. The volume must be 20% larger than the balloon would be at STP in order for the balloon ...
*April 25, 2016 by KS*

**Chemistry**

A helium balloon is filled to a volume of 2.88 x 10^3L at 722 mm Hg and 19 degrees Celcius. When the balloon is released, it rises to an altitude where the pressure and temperature are 339 mm Hg and -55vC, respectively. What is the volume of the balloon?
*February 10, 2011 by Ageha*

**science**

With the class watching from a safe (and dry!) distance below, suppose the student drops the balloon and the balloon hits the sidewalk with a force of 20 N. How much work was done on the sidewalk by the balloon?
*April 8, 2013 by Janny*

**physics**

Hot air balloon A is rising upward a rate of 5.0 m/s. A passenger aboard balloon A observes balloon B rising upward at a relative rate of 7.5 m/s. What is the velocity of balloon B relative to the ground? Assume that up is positive.
*June 15, 2015 by alex*

**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*

**chemistry**

A very flexible helium-filled balloon is released from the ground into the air at 20 degree C. The initial volume of the balloon is 5.00 L, and the pressure is 760 mmHg. The balloon ascends to an altitude of 20km, where the pressure is 76.0 mmHg and the temperature is -50 ...
*October 20, 2012 by Liang*

**chem**

A very flexible helium-filled balloon is released from the ground into the air at 20. ∘ C . The initial volume of the balloon is 5.00 L , and the pressure is 760. mmHg . The balloon ascends to an altitude of 20 km , where the pressure is 76.0 mmHg and the temperature is...
*March 18, 2015 by dakota*

**Algebra**

A balloon is secured to rope that is staked to the ground. A breeze blows the balloon so that the rope is taut while the balloon is directly above a flag pole that is 30 feet from where the rope is staked down. Find the altitude of the balloon if the rope is 100 feet long. ...
*February 21, 2016 by JACK*

**calculus**

A hot air balloon is rising vertically upward from the ground. The crew of a boat from a nearby lake notices this situation and looks upward at an angle of 10 degree to see the balloon. If the boat is 400meters away from the balloon, and the angle of observation is changing at...
*May 3, 2016 by rhakesh*

**Physics**

The instruments attached to a weather balloon have a mass of 5.2 kg. The balloon is released and exerts an upward force of 98 n on the instruments. A)what is the acceleration of the balloon and instruments? B) after the balloon has accelerated for 10s, the instruments are ...
*January 12, 2013 by Jules*

**calculus**

an air balloon is 80ft away from you with the angle of elevation of the rising balloon changing at a rate of 4 degrees per second how fast is the balloon rising when it is 6 feet off the ground.
*March 23, 2016 by marcos*

**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*

**Physics**

What minimum sized balloon would you have to fill in order to be able to be lifted into the air? Take your mass to be 100 kilograms and the temperature of the outside air to be 20 degrees C. Neglect the mass of the balloon rubber and basket and assume that the balloon is ...
*March 15, 2013 by steve*

**physics**

A water balloon is launched at a building 24m away with an initial velocity of 18 m/s at an angle of 50° above the horizontal. If the balloon misses or shoots over the building, how far will the balloon land from its launch location?
*October 13, 2014 by James*

**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*

**math**

the volume of a small balloon is 2 liters and a larger balloon is 5 liters. the small balloon is increased at a rate of 0.3 per sec. larger balloon is decreased at a rate of 0.12 liters per sec. after how many seconds will the two balloon have the same liters.
*February 13, 2013 by kitty*

**interoduction of aeronautical engineering**

Others say that the balloon was 23 metres high and 14 metres wide. Calculate the temperature of the air in the balloon (in degrees Celsius) for this situation as well. (Assume the balloon to be spherical, and then elongated by a factor 23/14 in height).
*July 14, 2015 by Shivam*

**Math**

If a person throws a water balloon, the height (in feet) if the water balloon is modeled by the equation: h=-16t^2-5t+100, where t is in seconds. When will the water balloon hit the ground?
*December 9, 2012 by Johanna*

**physics**

A water balloon is thrown into the air and lands 30.0 meters away 1.8 seconds later. a. What was the speed of the balloon thrown (on the diagonal) b. At what angle was the balloon thrown with respect to the ground?
*December 16, 2013 by sydney*

**physics. HELP**

A water balloon is thrown into the air and lands 30.0 meters away 1.8 seconds later. a. What was the speed of the balloon thrown (on the diagonal) b. At what angle was the balloon thrown with respect to the ground?
*December 16, 2013 by sydney*

**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*

**calculus**

A spherical balloon is being inflated at a rate of 10 cubic inches per second. How fast is the radius of the balloon increasing when the surface area of the balloon is square inches? Enter your answer correct to 3 decimal places.
*March 25, 2011 by Anonymous*

**science**

A weather balloon carries instruments that measure temperature, pressure, and humidity as it rises through the atmosphere. Suppose such a balloon has a volume of 1.2 m^3 at sea level where the pressure is 1 atm and the temperature is 20°C. When the balloon is at an altitude of...
*November 19, 2011 by Shirley*

**Physics**

A playful college student tosses a water balloon out of his dorm window at a speed of 6.2 m/s at an angle of 10° above the horizontal. The dorm window is 11 m above ground level. 1)What is the maximum height above the ground of the balloon? 2) At what time does the balloon ...
*April 21, 2014 by Corey Brown*

**Chemistry**

A weather balloon is inflated to a volume of 25.6L at a pressure of 736mmHg and a temperature of 31.9∘C. The balloon rises in the atmosphere to an altitude, where the pressure is 365mmHg and the temperature is -15.6∘C. Assuming the balloon can freely expand, ...
*February 22, 2015 by Candice*

**physics**

While riding in a hot air balloon, which is steadily descending at a speed of 1.39 m/s, you accidentally drop your cell phone. (a) After 4.00 s, what is the speed of the cell phone? (b) How far is the cell phone below the balloon after this time? d = m (c) What are your ...
*September 14, 2014 by Anonymous*

**physics**

While riding in a hot air balloon, which is steadily descending at a speed of 1.39 m/s, you accidentally drop your cell phone. (a) After 4.00 s, what is the speed of the cell phone? (b) How far is the cell phone below the balloon after this time? d = m (c) What are your ...
*September 14, 2014 by Dann*

**Calculus**

A spherical balloon is being inflated at a rate of 10 cubic inches per second. How fast is the radius of the balloon increasing when the surface area of the balloon is 2pi square inches? Enter your answer correct to 3 decimal places.
*March 28, 2011 by Anonymous*

**calculus**

A hemispherical dome has a diameter of 100m. A spotlight is placed on point B along the circumference on ground level. A balloon is released at point A on the center at a rate of 2m/s. how fast is the shadow of the balloon move on the roof when the balloon is 25m high?
*August 21, 2012 by arben*