# Posts by joane

Total # Posts: 34

**Physics**

An ideal spring hangs vertically from the ceiling. When a 1.0 kg mass hangs from the spring it is extended 5.0 cm from its relaxed length. A downward external force is now applied to the mass to extend the spring an additional 10 cm. While the spring is being extended by the ...

**Physics**

Einswine has a mass of 300 kg. He sits on an ideal spring. Before he sits on the spring it is 2 m tall. After he sits on the spring it is only 1.5 m tall. What is the spring constant of the spring?

**math**

C 0.65

**microeconomics**

Market demand is given as QD = 200 – 3P. Market supply is given as QS = 2P + 100. Each identical firm has MC = 0.5Q and ATC = 0.25Q. What quantity of output will a typical firm produce? a.10 b.20 c.30 d.40 Market demand is given as QD = 200 – 3P. Market supply is ...

**Physics**

Two loudspeakers emit sound waves along the x-axis. The sound has maximum intensity when the speakers are 35.9cm apart. The sound intensity decreases as the distance between the speakers is increased, reaching zero at a separation of 109.1cm. What is the wavelength of the ...

**Physics HELP!!**

1. What is the longest wavelength for standing sound waves in a 133.9cm long tube that is open at both ends? b).What is the second longest wavelength? c).What is the third longest wavelength? d).What is the longest wavelength for a standing wave, in the same length tube, that ...

**chemistry... HELPP**

Pyridine is a weak base that is used in the manufacture of pesticides and plastic resins. It is also a component of cigarette smoke. Pyridine ionizes in water as follows: C5H5N + H2O<-->C5H5NH+ + OH- The pKb of pyridine is 8.75. What is the pH of a 0.190 M solution of ...

**physics ..PLEASE HELP ASSIGN DUE SOON :(**

The sound intensity of 1.2x10-12J/m2s is the threshold of hearing for humans. What is the amplitude of the motion of the air molecules if the speed of sound in the air is 343m/s and the density of air is 1.28kg/m^3? Take the frequency of the air molecules as 1000 Hz

**Physics HELP!!**

A snapshot graph of a travelling wave is shown. The wave is travelling to the right at 18.2m/s. What is the amplitude if the maximum displacement is 19.9cm and the total distance travelled by the wave is 41.2m? b). What is the wavelength of the wave?

**Physics HELP!!**

The wave is travelling to the right at 18.2m/s. What is the amplitude if the maximum displacement is 19.9cm and the total distance travelled by the wave is 41.2m? b) What is the wavelength of the wave? c).What is the frequency of the wave?

**Physics !>:(**

A wave has angular frequency 46.2rad/s and wavelength 3.57m. What is its wave number? b).What is its wave speed?

**Physics HELP!!**

I am not getting the right answer for part b ! I don't know why though! :(

**Physics HELP!!**

a). What is the wavelengh of a 2.54MHz ultrasound wave travelling through aluminum?(the speed of sound in aluminum is 6420 m/s) b). What frequency of electromagnetic wave would have the same wavelength as the ultrasound wave above?

**Physics!!**

An athlete at the gym holds a 5.54kg steel ball in his hand. His arm is 80.4cm long and has a mass of 4.26kg. What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor? b).What is the magnitude of the torque ...

**Physics HELP!!**

Three masses are connected by massless rigid rods. Rods AC and CB have length l= 44.8cm. If massA=280.0g, massB=386.0g, and massC=739.0g, what are the coordinates of the center of mass? (Enter your answer for the x coordinate first, followed by the y coordinate.)

**Physics ~!!!!!!!**

A man of mass 76.1kg stands on a scaffold supported by a vertical rope at each end. The scaffold has a mass of 23.9kg and is 3.0m long. Suppose the man stands to the right from the middle of the scaffold that is a distance one sixth of the length of the scaffold. What is the ...

**Physics**

A block slides down a frictionless plane having an inclination of 18.9deg. If the block starts from rest at the top and the length of this incline is 2.21m, find the acceleration of the block. b). What is the block's speed when it reaches the bottom of the incline?

**Physics HELP!!**

A 4165.0kg truck is parked on a 15.8deg slope. What is the friction force on the truck?

**statistics!**

The following data represents the body mass index in a random group of twelve diabetic patients in a clinic. 18, 28, 31, 14, 25, 21, 22, 28, 35, 29, 27, 22. What is the z score of the person with the lowest and highest body mass index?

**statistics!**

1) Entry to a certain University is determined by a national test. The scores on this test are normally distributed with a mean of 500 and a standard deviation of 100. Tom wants to be admitted to this university and he knows that he must score better than at least 70% of the ...

**Physics**

A stubborn, 191.0kg mule sits down and refuses to move. To drag the mule to the barn, the exasperated farmer ties a rope around the mule and pulls with his maximum force of 854.0N. The coefficients of friction between the mule and the ground are s=0.790 and k=0.280. What is ...

**Physics**

A heavy freight train has a mass of 13200 metric tons. If the locomotive can pull with a force of 755000N, how long does it take to increase it's speed from 0 to 95.5 km/h?

**Physics HELP!!**

A student presses a book between his hands, as the drawing indicates. The forces that he exerts on the front and back cover are perpendicular to the book and are horizontal. The book weighs 29.7kg. The coefficient of static friction between his hands and the book is 0.44. To ...

**Physics**

How far apart are a proton and electron if they experience an electric force of 5.10N?

**physics ..PLEASE HELP ASSIGN DUE SOON :(**

A charge is to be placed at the empty corner to make the net force at corner A point along the vertical direction. What charge (magnitude and algebraic sign) must be placed at the empty corner if the three charges have the same charge of +7.63 μC?

**chemistry... HELPP**

Place charges and electron dots as needed on each ion. As Se Br K Ca Ga. I answered: As3+ Se2- Br- K+ Ca2+ Ga2+ but i got it wrong so please helppp!!!

**chemistry**

but i got it wrong .. sok PLEASE HELP!

**chemistry**

Place charges and electron dots as needed on each ion. As Se Br K Ca Ga. I answered: As3+ Se2- Br- K+ Ca2+ Ga2+

**physics ..PLEASE HELP ASSIGN DUE SOON :(**

A speedboat starts from rest and accelerates at +1.90m/s^2 for 7.00 s. At the end of this time, the boat continues for an additional 6.00 s with an acceleration of +0.529m/s^2. Following this, the boat accelerates at -1.47m/s^2 for 8.00 s. **What is the total displacement of ...

**Physics**

A ball is thrown vertically upward with a speed of 48.5m/s. What is the ball's velocity after 1.50s? ** B). what is the ball's height after 1.5 s?

**Physics**

A ball is thrown vertically upward with a speed of 48.5m/s. What is the ball's velocity after 1.50s? b) What is the ball's height after 1.5s?

**Physics**

While you are sitting on a park bench with your friend, you grab his hat and start running in a straight line away from him. Over the first 49.7m, you accelerate at 1.00m/s^2 up to your maximum running speed. You then continue at you maximum running speed for 7.02s more before...

**Physics**

I don't think b) is correct because im getting an incorrect answer

**physics**

A ballistic pendulum consists of a rectangular wooden block of mass 1.5 kg suspended from a ceiling. A bullet mass 0.025 kg undergoes a completely inelastic collision with the ballistic pendulum. Due to the collision the pendulum rises to a height of 45 cm. Calculate the speed...