7/17/2019 HW 4 Print

http://slidepdf.com/reader/full/hw-4-print 1/1

PHYS 221: Homework 4

Due Date: September 29 (Tuesday)

1. Chapter 2, Question 9, page 32 in H&,! "1# points$

9 In Fig. 2-22, a cream tangerine is thrown directly upward past three evenly spaced windows of equal

heights. Rank the windows according to (a) the average speed of the cream tangerine while passing them,

(b) the time the cream tangerine takes to pass them, (c) the magnitude of the acceleration of the creamtangerine while passing them, and (d) the change ∆v in the speed of the cream tangerine during the

passage, greatest first.

2. %rom the preious pro'(em, Question 2.9, the height o) ea*h win+ow is 1 m an+ the spa*e'etween win+ows is a(so 1 m. he tangerine was moing up with 12 m-s at the 'ottom o) win+ow 3. "12 points$

a. Calculate the average velocity of the tangerine while it is passing each window'. Calculate time the tangerine ta!es to pass each window*. Calculate the change in the velocity during each passing

3. Chapter 2, Pro'(em 9/, page 3/ in H&,! "0 points$

98 Two diamonds begin a free fall from rest from the same height, 1.0 s apart. How long after the first

diamond begins to fall will the two diamonds be 10 m apart?

4. 'a(( is +roppe+ )rom rest )rom the top o) a 'ui(+ing o) height h. t the same instant, a se*on+ 'a(( is proe*te+erti*a(( upwar+ )rom groun+ (ee(, su*h that it has ero spee+ when it rea*hes the top o) the 'ui(+ing. "1# points$

a. "hen do the two balls pass each other# $nswer it in terms of h'. "hich ball has greater speed when they are passing#*. "hat is the height of the two balls when they are passing#

0. Chapter 3, Pro'(em 15, page 06 in H&,! "/ points$

5. 7sing two e*tors, a an+ b )rom the preious pro'(em, Pro'(em 3.15, *a(*u(ate )o((owings in the unit e*tornotation8 "9 points$

a. %a & 'b '. 2ab 

*. %(a & 2b)(a)

6. Chapter 3, Pro'(em 65, page 51 in H&,! "0 points$

et 'oth e*tors,  A an+  B in the unit e*tor notation.;

76 A vector B, with a magnitude of 8.0 m, is added to a vector A, which lies along an x axis. The sum of these two vectors is a

third vector that lies along the y axis and has a magnitude that is twice the magnitude of A. What is the magnitude of A?