answr
Join / Login
Back

Important questions on Measurement Of Length

HARD

(a) At the time of this books printing, the U.S. national debt is about $ trillion. If payments were made at the rate of $ per second, how many years would it take to pay off the debt, assuming no interest were charged? (b) A dollar bill is about long. How many dollar bills attached end to end would it take to reach the Moon? The front end papers give the EarthMoon distance. Note: Before doing these calculations, try to guess at the answers. You may be very surprised.

View Answer
HARD

From the set of equations


 
involving the unknowns , and , find the value of the ratio of to .

View Answer
HARD

A hydrogen atom has a diameter of . The nucleus of the hydrogen atom has a diameter of approximately . (a) For a scale model, represent the diameter of the hydrogen atom by the playing length of an American football field ( yards = ft) and determine the diameter of the nucleus in millimeters. (b) Find the ratio of the volume of the hydrogen atom to the volume of its nucleus.

View Answer
HARD

Find every angle u between and for which the ratio of to is

View Answer
HARD

Prove that one solution of the equation
  is

View Answer
HARD

A high fountain of water is located at the center of a circular pool as shown in above figure. A student walks around the pool and measures its circumference to be . Next, the student stands at the edge of the pool and uses a protractor to gauge the angle of elevation of the top of the fountain to be . How high is the fountain?

View Answer
HARD

You stand in a flat meadow and observe two cows (Fig. above). Cow is due north of you and from your position. Cow is from your position. From your point of view, the angle between cow and cow is with cow appearing to the right of cow .  (a) How far apart are cow and cow ? (b) Consider the view seen by cow . According to this cow, what is the angle between you and cow ? (c) Consider the view seen by cow . According to this cow, what is the angle between you and cow ? Hint: What does the situation look like to a hummingbird hovering above the meadow? (d) Two stars in the sky appear to be apart. Star is from the Earth, and star , appearing to the right of star , is from the Earth. To an inhabitant of a planet orbiting star , what is the angle in the sky between star and our Sun?

View Answer
HARD

parsec = __________ metres

View Answer
HARD

A student measured the length of a rod and wrote it as . Which instrument did he use to measure it?

A

A meter scale

B

A vernier calliper where the divisions in vernier scale matches with division in main scale and main scale has divisions in

C

A screw gauge having divisions in the circular scale and pitch as

D

A screw gauge having divisions in the circular scale and pitch as

View Answer
HARD

The nearest star to our solar system is 4.29 light years away. How much is this distance in terms of parsecs? How much parallax would this star (named Alpha Centauri) show when viewed from two locations of the Earth six months apart in its orbit around the Sun ?

View Answer