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# density multiple choice questions

Question:Q1.Matching the following terms with their correct definitions or examples. 1.community 2.biome 3.habitat 4.population a. a group of populations b. a group of the same species in the same area c. grasslands or tundra d. the place an organism lives Q2.The relationships of plants and animals to each other and their environment is what ecologists call _____. a.ethology b.an ecosystem c.a biome d.an environmental group Q3.Biotic factors cannot live without abiotic factors. a.True b.False Q4.A coniferous forest is an example of a _____. a.biome b.community c.habitat d.population Q5.The acacia tree provides a habitat and protection for ants. This is considered its _____. a.biome b.ecological niche c.ecosystem d.biotic factor Q6._____ refers to a balanced ecosystem. a.Great equality b.Dynamic equilibrium c.Grand balance Q7.In a 10 m2 ecosystem, there are 60 raccoons. What is the population density of raccoons? a.6 per m2 b.10 per m2

Answers:Q1 1.community- A 2.biome- C 3.habitat- D 4.population- B Q2 B Q3 True Q4 A Q5 B Q6 B Q7 A

Question:1) Which of the following is the correct order of steps to establish a theory? a) conducting experimental work, collecting observations, making a hypothesis, establishing a theory. b) establishing a theory, conducting experimental work, collecting observations, making a hypothesis. c) making a hypothesis, collecting observations, establishing a theory, conducting experimental work. d) collecting observations, making a hypothesis, conducting experimental work, establishing a theory. 2) Which of the following units would best describe the distance between two asteroids hat at 8 deca hecto kilo miles apart? a) gigamile b) Teramile c) Macromile d) megamile 3) a rectangular tile, 15 by 18 inches, can be converted into square meters by which one of the following conversion setups? a) (15in x 18in)(2.54cm/1in)(1m/100cm) b) (15in x 18in)(2.54cm/1in)^2(1m/100cm) c) (15in x 18in)(2.54cm/1in)^2(1m/100cm)^2 d) (15in x 18in)(2.54cm/1in)(1m/100cm)^2 4) Calculate the density, in kg/L, of a block of wood 2.5 feet by 18 inches by 1 yard that weighs 646lbs. a) .92 kg/L b) 9.2 kg/L c) 1.1 kg/L d) 4.9 kg/L the second question should say 'that are' not hat at.

Answers:1) Which of the following is the correct order of steps to establish a theory? d) collecting observations, making a hypothesis, conducting experimental work, establishing a theory. 2) Which of the following units would best describe the distance between two asteroids hat at 8 deca hecto kilo miles apart? d) megamile 3) a rectangular tile, 15 by 18 inches, can be converted into square meters by which one of the following conversion setups? c) (15in x 18in)(2.54cm/1in)^2(1m/100cm)^2 4) Calculate the density, in kg/L, of a block of wood 2.5 feet by 18 inches by 1 yard that weighs 646lbs. b) 9.2 kg/L

Question:Help! Physics! Yuck! I have an exam next week on this optics and lenses stuff and our teacher gave us a sample Multiple Choice paper to work through......... I got about 80% of them but I can't figure out the answers for these ones. Can you help? Thanks! p.s. I don't need the whole method and how to work out the whole question lol I still need a challenge :)! I'd like to try and get them myself but sometimes I find it easier to work out the method going backwards from the answer if you get me! I just really don't get these ones. Maybe you can give me the answer i'm aiming for and clue of the method to get me going? If I'm really stuck I'll post the ones I still don't understand later and maybe ask for a bit more help! thnx guys xxxxxx :) stacey x ps even if you can just help with one of them thats fine! ok so here's the questions A patient's eye has an optical power of 63 dioptres. The patient wears glasses of power -7 dioptres. What is the combined optical power of the eye and glasses? a.5.7 dioptres b.56 dioptres c.70 dioptres d.6.3 dioptres An object is placed 20 cm from a lens with a positive focal length of 5 cm. What is the separation of the image position from the lens? a.Greater than 10m on the opposite side of the lens from the object b.20 cm on the opposite side of the lens from the object c.7 cm on the opposite side of the lens from the object d.7 cm on the same side of the lens as the object A string vibrates with a fundamental frequency of 400Hz. What is the wavelength of the sound emitted? Take the speed of sound to be 340m/s. a.1.18 cm b.1.4 m c.0.85 m d.0.25 cm What is the wavelength of light in the vitreous humour of the eye, where the wavelength of the light is 0.64 m in air? Take the refractive index of the vitreous humour to be 1.3 and the refractive index of air to be that of a vacuum. a.0.64 m b.0.49 m c.1.94 m d.0.83 m A lens has one convex radius of curvature of 0.2 m and one concave radius of curvature of 0.4 m for the two surfaces. What is the focal length of the lens? Take the lens refractive index to be 1.5. a.0.27 m b.0.6 m c.-0.8 m d.0.8 m How many of the following statements are correct? i) In reflection, the angle of incidence is equal to the angle of reflection ii) A specular reflection occurs at a rough surface iii) Two mirrors placed at right angles to each other can return a light ray to be parallel to its original direction iv) A reflection can occur at an interface between differing refractive indices. a.1 statement b.4 statements c.2 statements d.3 statements A fly of length 4 mm is illuminated with a spot light and a magnifying glass is positioned 5 cm from the fly. An image screen is placed on the other side of the lens at a separation of 30 cm from the lens. How long is the image of the fly on the screen? 37.5 mm 20 mm 24 mm 0.7 mm A glass plate with a refractive index of 1.5 is inserted in to a beam such that the angle of incidence is 30 degrees from the normal of the plate. Through what angle is the ray inside the plate deviated from that of the incident ray? a.0 degrees b.10.5 degrees c.19.5 degrees d.30 degrees A glass plate is inserted in to a beam such that the angle of incidence is 30 degrees from the normal of the plate. Through what angle is the ray that is transmitted through the glass plate deviated from that of the incident ray? Take the plate to have parallel surfaces and a refractive index of 1.5. a.15 degrees b.0 degrees c.30 degrees d.50 degrees Light in a refractive index 1.5 is incident at an interface with air of refractive index 1. For total internal reflection, what is the minimum angle of incidence relative to the normal at the interface i.e., the critical angle? a.34 degrees b.48 degrees c.20 degrees d.42 degrees If the sound intensity level of one person speaking is 50dB, what is the sound intensity level where 4 people are speaking? a.200 b.50 c.56 d.90 An ultrasound echo from the midline of the brain is detected back at the ultrasound instrument 0.1 miliseconds after the source pulse is emitted from the same instrument. How far from the source is the midline? Assume that the speed of sound in the brain tissue is 1540m/s. a.7.7 cm b.15.4 cm c.30.8 cm d.30.8 mm What focal length is given by the cornea? For your calculation, take the radius of curvature of the cornea to be 7.0 mm and approximate the cornea to act as a lens in air with one side curved and the other side plane. Take the refractive index of the cornea to be 1.40. a.0.2 mm b.5.0 mm c.6.0 mm d.17.5 mm

Answers:Q1. None of the answers are correct. The teacher is probably looking for answer b as you can generally add lens powers (reciprical of focal length). However, this is only true for thin lenses in contact. In this case the eye lens and spectacle lens are both thick and seperated. Q2. Use the lens equation 1/u + 1/v = 1/f If you don't recognize this then you are in real trouble Q3. Use the formula frequency x wavelength = speed. Make sure all your values are in the same units. Q4. Frequency x wavelength = speed As the frequency is constant then you can calculate the different wavelength knowing how the speed changes. Speed in medium = speed in air(vacuum) / n Q5. Power of a thin lens k = (n-1)(c1 - c2) where c1 and c2 are the surface curvatures. (Note that the signs are opposite for each side of a convex lens.) Focal length = 1/k Q6. All are true except ii That's enough for now.

Question:Question 1 Solve the equation: 2z^3 + 2z^2 12z = 0 A. 0, -2, 3 B. 0, 2, -3 C. 2, -3 D. -2, 3 Question 2 Factor completely: 9x^3 3x^2 6x A. 3x(3x + 2)(x 1) B. (3x + 2)(x 1) C. (3x^2 + 2x)(3x 3) D. 3x(3x^2 + 2x)(3x 3) Question 3 The length of a rectangle is 4m more than twice the width. If the area of the rectangle is 160m^2, find the dimensions. A. 8m by 10m B. 8m by 20m C. 10m by 24m D. 10m by 16m Question 4 Factor completely: p^2 + 9p + 14 A. (p 7)(p + 2) B. (p + 7)(p 2) C. (p 7)(p 2) D. (p + 7)(p + 2) Question 5 Which one of the following is irreducible and therefore is a prime polynomial? A. 3m^2 - 4mn - n^2 B. 3m^2 2mn n^2 C. 3m^2 + 4mn + n^2 D. 3m^2 + 2mn n^2

Answers:1. B 2. A 3. B 4. D 5. A