# College Physics: Multiple Choice Questions

Pages: 548 (104344 words) Published: October 21, 2012
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Introduction

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1 http://helpyoustudy.info

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Chapter 1

8.

The given Cartesian coordinates are x = −5.00, and y = 12.00 , with the least accurate containing 3 signiﬁcant ﬁgures. Note that the speciﬁed point (with x < 0 and y > 0 ) is in the second quadrant. The conversion to polar coordinates is then given by: r = x 2 + y 2 = ( −5.00 ) + (12.00 ) = 13.0 2 2

tan θ =

y 12.00 = = −2.40 x −5.00

and θ = tan −1 ( −2.40 ) = −67.3° + 180° = 113°

Note that 180° was added in the last step to yield a second quadrant angle. The correct answer is therefore (b) (13.0, 113°). 9. Doing dimensional analysis on the ﬁrst 4 given choices yields: (a)

[ v]
⎡t ⎤ ⎣ ⎦
2

=

LT L = 3 T2 T

(b)

[ v]
⎡x2 ⎤ ⎣ ⎦

=

LT = L−1T −1 L2

(c)

⎡ v 2 ⎤ ( L T )2 L2 T 2 L2 ⎣ ⎦= = = 3 T T T [t ]

(d)

⎡ v 2 ⎤ ( L T )2 L2 T 2 L ⎣ ⎦= = = 2 L L T [ x]

Since acceleration has units of length divided by time squared, it is seen that the relation given in answer (d) is consistent with an expression yielding a value for acceleration. 10. The number of gallons of gasoline she can purchase is # gallons = total expenditure 33 Euros ≈ cost per gallon ⎛ Euros ⎞ ⎛ 1 L ⎞ ⎟ ⎜ 1.5 ⎟⎜ L ⎠ ⎜ 1 quart ⎟ ⎝ ⎝ ⎠ ≈ 5 gal

⎛ 4 quarts ⎜ ⎜ 1 gal ⎝

⎞ ⎟ ⎟ ⎠

so the correct answer is (b). 11. The situation described is shown in the drawing at the right. h From this, observe that tan 26° = , or 45 m h = ( 45 m ) tan 26° = 22 m 26

h

Thus, the correct answer is (a). 12.

45 m

Note that we may write 1.365 248 0 × 10 7 as...