# Rose

### What would you expect the concentration of pollutant X to be on trophic level 2 and 4?

The ecological efficiency in a food chain is 10 percent. Pollutant X is transferred up the food chain from one trophic level to the next with an efficiency of 30 percent.

The concentration of X on trophic level 2 is 30 ppm.

If the concentration of X on other trophic levels in the food chain is determined entirely by food chain magnification, what would you expect the concentration of X to be on

a) Trophic level 2?

b) Trophic level 4?

Biology11 months ago### How big of a pot should I get for a Calathea Ornata (Pinstripe Plant)?

I just purchased a young Calathea Ornata (Pinstripe Plant). The internet says it will grow to 2 ft. How big of a pot should I get for this plant? I want to make sure I get a good size for maximum growth.

1 AnswerGarden & Landscape1 year ago### Weight loss: How do I lose these last 3 pounds?

So I decided to go on a diet this past November after gaining 5 POUNDS from Halloween candy (Reese's are so addictive). It just sort of made me realize that I could be WAY healthier. Since November I have lost 22 pounds from diet and exercise, but I've reached a major plateau and I don't know what else to do. I was originally 155lbs and my goal is 130lbs. I know these are just numbers and all, but hitting a goal feels too good not to push for it.

I started out doing just exercise, then exercise and calorie deficits (I mixed this up anywhere between 500 to 1000 calories) then I tried eating a sustainable amount of food for my body to give it a break, then I took a small break from exercise, then I tried low carb, and then I tried low carb and light exercise (can't go too hard or I get sick, I tried). I've just been trying to keep my body guessing.

I feel like I've used every option I've read about or heard about from friends. I've tried adding more protein to my diet, green tea, more sleep etc. I want to start weights but really wanted to start after I hit my weight loss goal.

Any advice?

89 AnswersDiet & Fitness1 year ago### Wastewater treatment: If you were a consultant to the city, which option would you recommend that they take and why?

The effluent from a wastewater treatment plant is being discharged into a lake, and because of that fact the lake is experiencing serious cultural eutrophication problems. The city operating the plant is considering two alternative forms of tertiary nutrient removal, the first of which would reduce the N concentration in the effluent to 1 ppm and the second of which would reduce the P concentration in the effluent to 1 ppm. Both options cost exactly the same amount of money. The city can afford only one of the options.

1 AnswerEarth Sciences & Geology2 years ago### Which sedimentation basin do you think will do a better job of minimizing nonpoint source pollution and why?

A contractor is hired to build a condominium on a parcel of land with an area of 4 hectares. In an effort to minimize runoff from the construction site, the contractor builds a sedimentation basin with a depth of 3 meters and an area of 400 m^2. At the same time a nearby town decides to build a sedimentation basin to intercept runoff from the town that is polluting a recreational lake. The town occupies an area of 250 hectares. About 50 percent of the town consists of impervious surfaces such as streets, parking lots, and roof tops. The town builds a sedimentation basin with a depth of 3 meters and an area of 4,000 m^2.

Earth Sciences & Geology2 years ago### What is the optical depth associated with the eutrophic zone?

Given equation: ln(Io/I)

I=irradiance at particular depth

Io=irradiance at surface

Base eutrophic zone is the depth at which I=1 percent of Io

Can someone explain to me how to go about solving this question? I've only ever done it with actual values for I and Io.

1 AnswerPhysics2 years ago### What is the unstrained length of the cord?

A 7.2-kg bowling ball is attached to the end of a nylon cord with a cross-sectional area of 3.75 x10^-5 m2. The other end of the cord is fixed to the ceiling. When the bowling ball is pulled to one side and released from rest, it swings downward in a circular arc. At the instant it reaches its lowest point, the bowling ball is 1.6 m lower than the point it was released from, and the cord is stretched 2.51 x10^-3 m from its unstrained length. What is the unstrained length of the cord? Hint: When calculating any quantity other than the strain, ignore the increase in the length of the cord.

1 AnswerPhysics2 years ago### If the skier's acceleration up the slope has a magnitude of 0.9 m/s2, what is the original (unstretched) length of the cable?

A 57-kg snow skier is being pulled up a 13° slope by a steel cable. The cable has a cross-sectional area of 7.23x10^-5 m2. The cable applies a force to the skier, and, in doing so, the cable stretches by 2.04 x10^-4 m. A frictional force of magnitude 62 N acts on the skis and is directed opposite to the skier's motion.

1 AnswerPhysics2 years ago### What is the radius of the wire at the same strain as the spider's thread, when the thread is stressed by the full weight of the spider?

A 9.00x10^-4kg spider is hanging vertically by a thread that has a Young's modulus of 1.20x10^8 N/m^2 and a radius of 1.50x10^-5 m. Suppose that a 87-kg person is hanging vertically on an aluminum wire.

1 AnswerPhysics2 years ago### Find the tension in the wire when the tuning peg is turned through two revolutions.?

One end of a piano wire is wrapped around a cylindrical tuning peg and the other end is fixed in place. The tuning peg is turned so as to stretch the wire. The piano wire is made from steel (Y = 2.0x10^11 N/m^2). It has a radius of 0.76 mm and an unstrained length of 0.81 m. The radius of the tuning peg is 2.0 mm. Initially, there is no tension in the wire, but when the tuning peg is turned, tension develops. Find the tension in the wire when the tuning peg is turned through two revolutions. Ignore the radius of the wire compared to the radius of the tuning peg.

1 AnswerPhysics2 years ago### Find the magnitude and direction of the sum of momenta of the two joggers.?

An 85-kg jogger is heading due east at a speed of 1.5 m/s. A 55-kg jogger is heading 32° north of east at a speed of 3.8 m/s. Find the magnitude and direction of the sum of momenta of the two joggers.

The magnitude is 328.4, but I can't get the angle correct for some reason! Please Help!

2 AnswersPhysics3 years ago### How much work (in Joules) can a 3.0 hp lawnmower engine do in 1 hour? ?

(1hp = 746 W and 1 h = 3600 s).

2 AnswersEngineering3 years ago### At what height is its speed equal to v/2?

A block slides down a smooth ramp, starting from rest at a height h. When it reaches the bottom, it’s moving at speed v. It then continues to slide up a second smooth ramp. At what height is its speed equal to v/2?

1 AnswerPhysics3 years ago### What is the speed at which the satellite travels?

A satellite is in a circular orbit about the earth (ME = 5.98E24 kg). The period of the satellite is 4.20E4s.

2 AnswersPhysics3 years ago### Is the upward force of a seat at the top of a ferris wheel greater less or equal to the passenger's weight?

At the top of a Ferris wheel, is the upward force the seat applies to the passenger greater than, less than, or equal to the passenger’s weight? Explain.

8 AnswersPhysics3 years ago### What would be the satellites's orbital period?

A satellite with mass (m) has a period of orbital (p) when it is in a circular orbit of radius (r) around a planet. If the satellite instead had a mass of 3m, what would be its orbital period?

Answer in terms of p

1 AnswerPhysics3 years ago