college Physics

posted by .

Dear Sir,
Please help. I am struggling with the below problems for a very long time.
thanks
Larry King


1) Suppose that in a certain atmospheric situation, a falling raindrop, having an initial mass of 0.010g. collects smaller droplets by collision at such a rate that, after 10s, it has a mass of 0.020g g and a diameter of 3.4 mm.
(a) If the droplet continues to gain mass at the same average rate as it continues to fall, what will its diameter at the end of the next 10 s? (Using a scale and ratio reasoning, not substitution in formulas, and explain what you are doing.)
(b) If 3.4 mm a reasonable or unreasonable order of magnitude for the diameter of a droplet with a mass of 0.020g? ( Make a crude, quick estimate- not an elaborate calculation- and explain your reasoning)










2 ) A statue is to be scaled down, without distorting its shape, by changing its total volume from 1.25m3 . Explain your reasoning in each of the following calculations.
(a) If the height of the original statue is 250cm, calculate the height of the smaller model.
(b) If the circular base of the original statue has a circumference of 45 cm, calculate the circumference of the scaled-down base in the smaller model.
(c) How will the total surface area of the model compare (this means an appropriate ratio) with the total surface area of the original? How will the surface areas of the circular bases compare?
(d) If both the model and the original are made of the same material, how will the mass of model compare with mass of the original?
(e) If the model and the original are not made of the same material, what would you have to know about the materials to be able to compare the masses, and how would you use this information?
(f) If the original statue and the model turned out to have the same mass, what would you conclude about the materials making up the two objects? (Give a numerical answer comparing relevant properties of the materials.)

2) As a first approximation, let us think of an older person O as being a larger scale model of a younger person Y, with lengths in all parts of the body increased by the same scale factor. Suppose the weight of O is 4.50 times the weight of Y.

(a) If height of O is 6.0 ft, what must be the height of Y?

(b) How will the cross-sectional area at some level in the legs of the older person compare with the cross-sectional area at the corresponding level in the legs of the younger?

(c) Will the compressional stress on the leg bones be the same in the two individuals? (“Stress” is the name for the force per unit area that the bone must support.) Why or why not? If not, for which individual will the stress be greater? By what numerical factor? It is because of the effect that emerges in the analysis you have just conducted that larger animals are, in reality in the world around us, not simply scaled-up models of smaller animals. Explain the reasoning behind this statement.

  • college Physics -

    No wonder that you are struggling, they are invisible.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. computers

    Dear Sir, thanks very much for your the very detail instruction which I am still working on it. I need some help in using Microsoft Excel to format rational number in the form a/b( not in reduced form :eg. 3/6 but Excel will return …
  2. Physics

    dear Sir, I have some questions based on proportional reasoning and I hope you can help me thanks Larry king 1.5 Suppose that in a certain atmospheric situation, a falling raindrop, having an initial mass of 0.010g. collects smaller …
  3. college physics

    Please help! the below questions are driving me crazy. Thanks Larry King 1) Suppose that in a certain atmospheric situation, a falling raindrop, having an initial mass of 0.010g. collects smaller droplets by collision at such a rate …
  4. maths

    Dear Sir I need help for the below questions Please help thanks larry King 1) Sally bought some erasers and pens 16.50. She bought 5 fewer erasers than pens. Each erasers cost $1.80 more than the pen. How many pens did she buy?
  5. Physics

    A raindrop (mass=1.00g) is travelling at a speed of 40m/s when it hits the surface of 100g of water contained in a drinking glass. What is the change in temperature of the water in the glass if we assume that i)all the kinetic energy …
  6. physics/math

    A spherical raindrop of mass 0.0108 g and radius 1.37 mm falls from a cloud that is at a height of 1165 m above the ground. Assume the drag coefficient for the raindrop is 0.60 and the density of the air is 1.3 kg/m3. What is the raindrop's …
  7. English

    Is it B? What is the main idea of the story of Morte d’Arthur by Sir Thomas Malory?
  8. physics

    A raindrop has a mass of 5.6 × 10-7 kg and is falling near the surface of the earth. Calculate the magnitude of the gravitational force exerted (a) on the raindrop by the earth and (b) on the earth by the raindrop.
  9. writting skills

    For the greeting in a business letter when you don't know the name of the person who will be reading it, which of the following is least likely to conform to present-day usage?
  10. Enghlish

    What is the main idea of the story of Morte d’Arthur by Sir Thomas Malory?

More Similar Questions