# Posts by Orla

Total # Posts: 27

**PHYSICS**

When a person wears a hearing aid, the sound intensity level increases by 35 dB. By what factor does the sound intensity increase?

*April 6, 2016*

**PHYSICS**

An amplified guitar has a sound intensity level that is 11 dB greater than the same unamplified sound. What is the ratio of the amplified intensity to the unamplified intensity?

*April 6, 2016*

**PHYSICS**

Assuming an object at infinity, a person has far points of 5.2 m from the right eye and 6.2 m from the left eye. Describe the lens required (diopters) as seen in a prescription for the refractive power of each corrective contact lens.

*April 6, 2016*

**physics**

The distance between the lenses of a microscope is 18 cm. The focal length of the eyepiece is 1.8 cm. If the microscope is to produce an angular magnification of -260 when used by a person with a normal near point (20 cm from the eye), what must the focal length of the ...

*April 6, 2016*

**Physics**

An object has an angular size of 0.0140 rad when placed at the near point (20.0 cm) of an eye. When the eye views this object using a magnifying glass, the largest possible angular size of the image is 0.0490 rad. What is the focal length of the magnifying glass?

*April 6, 2016*

**Physics**

The mass of a string is 6 grams, and it is stretched so that its tension is 150 N. A transverse wave travelling on this string has a frequency of 160 Hz and a wavelength of 0.40 m. What is the length of this string? (ii) A chain saw has a measured sound level of 80 dB. What is...

*April 6, 2016*

**PHYSICS**

A string on a violin is tuned to vibrate at a fundamental frequency of 65.0 Hz. If the tension in the string were increased by a factor of three, what would be the new fundamental frequency?

*April 6, 2016*

**Maths *have answer, want method* Urgent!**

82.64%

*April 13, 2013*

**Maths *have answer, want method* Urgent!**

Suppose that the blood pressure of the human inhabitants of a certain Pacific island is distributed with mean, \mu = 108 mmHg and standard deviation , \sigma = 6 mmHg. According to Chebyshev's Theorem, at least what percentage of the islanders have blood pressure in the ...

*April 13, 2013*

**Calculus**

40/8=5 .75^5=0.2373 100-23.73=76.27% thanks :)

*March 11, 2013*

**Calculus**

The area of a wetland drops by 1/4 every 8 years. What percent of its total area disappears after 40 years? Percent lost %?

*March 11, 2013*

**Physics**

Can anyone help with the following? I think i have the answer i would just like to verify that it is correct, An equipotential surface that surrounds a point charge q has a potential of 490 V and an area of 1.1 m2. Determine q

*February 13, 2013*

**Physics**

In doing a load of clothes, a clothes dryer uses 16 A of current at 240 V for 45 min. A personal computer, in contrast, uses 2.7 A of current at 120 V. With the energy used by the clothes dryer, how long (in hours) could you use this computer to surf the Internet?

*February 13, 2013*

**physics**

Dolphins emit clicks of sound for communication and echolocation. A marine biologist is monitoring a dolphin swimming in seawater where the speed of sound is 1523 m/s. When the dolphin is swimming directly away at 5.5 m/s, the marine biologist measures the number of clicks ...

*January 18, 2013*

**Physics**

A bat emits a sound whose frequency is 83.2 kHz. The speed of sound in air at 20.0 oC is 343 m/s. However, the air temperature is 40.5 oC, so the speed of sound is not 343 m/s. Assume that air behaves like an ideal gas, and find the wavelength of the sound.

*January 15, 2013*

**Physics (Please, it's a minor error)**

A rectangular block has dimensions 1.5cm x 3.2cm x 3.9cm and a mass of 61g. Determine the density in SI units My taking on the question, Mass= 0.061kg Volume= 0.1872m Density=0.061kg/0.1872m=0.3258547kgm^-3 Can someone please tell me where I'm going wrong?

*November 19, 2012*

**Physics**

John’s mass is 81.0 kg, and Barbara’s is 62.4 kg. He is standing on the x axis at xJ = +9.41 m, while she is standing on the x axis at xB = +4.34 m. They switch positions. How far and in which direction does their center of mass move as a result of the switch? ...

*November 7, 2012*

**algebra**

Domain: The domain of a function is the set of all possible input values (usually x), which allows the function formula to work. Range: The range is the set of all possible output values (usually y), which result from using the function formula.

*October 30, 2012*

**Physics**

You are working out on a rowing machine. Each time you pull the rowing bar (which simulates the oars) toward you, it moves a distance of 1.2 m in a time of 1.4 s. The readout on the display indicates that the average power you are producing is 78 W. What is the magnitude of ...

*October 30, 2012*

**Chemistry**

A 0.5370 g sample of a pure soluble chloride compound is dissolved in water, and all of the chloride ion is precipitated as AgCl by the addition of an excess of silver nitrate. The mass of the resulting AgCl is found to be 1.2523 g. What is the mass percentage of chlorine in ...

*October 25, 2012*

**Physics**

A satellite has a mass of 6179 kg and is in a circular orbit 4.83 × 105 m above the surface of a planet. The period of the orbit is 2.4 hours. The radius of the planet is 4.03 × 106 m. What would be the true weight of the satellite if it were at rest on the planet...

*October 25, 2012*

**Physics**

A speed skater goes around a turn that has a radius of 31 m. The skater has a speed of 13 m/s and experiences a centripetal force of 460 N. What is the mass of the skater?

*October 25, 2012*

**Physics**

A satellite has a mass of 6179 kg and is in a circular orbit 4.83 × 105 m above the surface of a planet. The period of the orbit is 2.4 hours. The radius of the planet is 4.03 × 106 m. What would be the true weight of the satellite if it were at rest on the planet...

*October 23, 2012*

**Physics**

Thank you for the answer, I probably should have specified that I only wanted a formula to help me figure it out, but thanks :)

*October 19, 2012*

**Physics**

On earth, two parts of a space probe weigh 18300 N and 4440 N. These parts are separated by a center-to-center distance of 5.11 m and may be treated as uniform spherical objects. Find the magnitude of the gravitational force that each part exerts on the other out in space, far...

*October 19, 2012*

**Physics**

Traveling at a speed of 19.3 m/s, the driver of an automobile suddenly locks the wheels by slamming on the brakes. The coefficient of kinetic friction between the tires and the road is 0.620. What is the speed of the automobile after 1.46 s have elapsed? Ignore the effects of ...

*October 19, 2012*

**maths stats**

Please unscramlbe aaeebllnn which is a name. Thanks

*May 5, 2011*

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