PRACTICE PAGE (2)

.pdf

School

Lansing Community College *

*We aren’t endorsed by this school

Course

111

Subject

Physics

Date

Oct 30, 2023

Type

pdf

Pages

Uploaded by SuperHumanPowerGoat18

Name l 4 CONCEPTUAL Phys: PRACTICE PAGE B\ L Date Chapter 9 Gravity Inverse-Square Law and Weight 1. Paint spray travels radially away from the nozzle of the can in straight lines. Like gravity, !r?e strength (intensity) of the spray obeys an inverse-square law. Complete the diagram by filling in the blank spaces. 1 AREA UNIT |4 AREA UNITS '(#)AREA UNITS] () AREA UNITS PAINT SPRAY |1 mm THICK | % mm THICK | (%) mm THICK | ¢45) mm THICK 2 . . o i i i lluminates a wall behind. 2. A small light source located 1 m in front of an opening of area 1 m" illumin If the wal?is 1 m behind the opening (2 m from the light. source), the illuminated area covers 4m°. How many square meters will be illuminated if the wall is 5 m from the source? _ZS_W‘; {'m? OPENING : e 4 : m 10 m from the source? (Q4M i E:l/ : ILLUMINATION SOURCE i on a weighing scale and find that we are pulled toward Earth with a force of : gc‘)’ger\ls‘?}?:na\:v;e:\:eigh &4 "g N.gStrictIy speaking, we weigh£0¢ N re_:lat.ive to Earth. How much does éarth weigh? If you tip the scale upside down and repeat the weighing process, we can say that we and Earth are still pulled together with a force of_S Q9 N,and the}'efore, rglatlve to us, the whole 6,000,000,000,000,000,000,000,000-kg Earth weighsS ¢ o N! Weight, unlike mass, is a relative quantity. - VIEW THE SAME FROM ANOTHER PERSPECTIVE / DO YOU SEE WHY IT MAKES SENSE TO DISCUSS THE EARTH'S MASS, BUT NOT ITS WEIGHT? We are pulled to Earth with a force Earth is pulled toward us with a force of 500 N, so we weigh 500 N. of 500 N, so it weighs 500 N. :ImT.’ 51

CONCEPTUAL PllySiCS PRACTICE PAGE T Chapter 9 Gravity : e Inverse-Square Law and Weight—continue 4. The spaceship is attracted | to both the planet and the planet's moon. The planet \ has four times the mass of its moon. The force of \ attraction of the spaceship to the planet is shown by ,4/ the vector. — Rl a. Carefully sketch another 3 % s vector to show the spaceship’s attraction to the moon. Then apply the \ i parallelogram method of Chapter 5 and 4D f\" sketch the resultant force. b. Determine the location between the planet and its moon (along the dotted line) where gravitational forces cancel. Make a sketch of the spaceship there. 5. Consider a planet of uniform density that has a straight tunnel from the North Pole through the center to the South Pole. At the surface of the planet, an object weighs 1 ton. a. Fill in the gravitational force on the object when it is half way to the center, then at the center. b. Describe the motion you would experience if you fell into the tunnel. ba(k omd £dT M gTlo | 6. Consider an object that weighs 1 ton at the surface of a planet, just before the planet gravitationally collapses. (The mass of the planet remains the same during collapse.) a. Fill in the weights of the object on the planet's shrinking surface at the radial values show™ 1T°N/‘~ AN P S Sl e e P W T PR T S *‘__’__TON A—j_TGN rﬂ??.'r‘"“ > 2% %o puts AN : i erected tha ition- |anet has collapsed to one-tenth of its initial radius, a Igdder is his posit & :/1\1/: ?Jrl,)j?:t 25 far from its center as the object was originally. Fill in its weight at! el

CONCEPTUAL P IlySiC PRACTICE PAGE Chapter 9 Gravity QOur Ocean Tides 1. Consider two equal-mass blobs of w. ater, A and B, initially at rest in the Moon's A 2 gravitational field. The vector shows the <~ <& gravitational force of the Moon on A. a. Draw a force vector on B due to the Moon’s gravity. b. Is the force on B more or less than the force on A? LED 5 E Why? (15 felther oWe J d. The blobs accelerate toward the Moon. Which has the greater acceleration? ([A]) [B] e. Because of the different accelerations, with timeé [A gets farther ahead of B] [A and B gain identical speeds] and the distance between A and B fincreases] ) [stays the same] [decreases]. £, If A and B were connected by a rubber band, with time the rubber band would [not stretch]. g. This stretching]. [non-stretching] is due to the @f—er*enc;]) [non-difference] in the Moon’s gravitational pulls. e e h. The two blobs will eventually crash into the Moon. To orbit around the Moon instead of crashing into it, the blobs should move [away from the Moon] 7tanrgally Then their accelerations will consist of changes in [speed] [direction]; A B 2. Now consider the same two blobs p & @ of Earth. 74 7 located on opposite sides a. differences in the Moon’s pull on the blobs, they tend to [spread away from each other] [approach each other]. Bs L2 et o b. Does this spreading produce ocean tides?("[;('es] ) [No] c lf arth and Moon were closer, gravitationnaglrforce between them would be [more] > [the same] [less], and the difference in gravitational forces on the near r parts of the ocean would be <@o_r3]) [the same] [less]. d. gecaus;: Earth’g orbit about Fhe Sun is slightly elliptical, the Earth and Sun are closer in ecember than in June. Taking the Sun'’s tidal force into account, on a world average, ocean tides are greater in ([December] ~ [June] [no di b ifference). |

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version