This preview shows page 1. Sign up to view the full content.
Unformatted text preview: This gives the elapsed time when they meet as t = 2.15 (a) v= (b) v = (c) v= 10.0 m − 0
= 5.00 m s
2.00 s − 0 ( 5.00 − 10.0) m ( 4.00 − 2 .00) s x(m)
10
8
6
4
2
0
–2
–4
–6 = − 2.50 m s ( 5.00 − 5.00) m
=
( 5.00 − 4.00) s 0 25 1234567 8 t(s) CHAPTER (d) v = ( 8.00 − 7.00) s = 5.00 m s (a) A few typical values are
t(s)
1.00
2.00
3.00
4.00
5.00
6.00 200
180 x(m)
5.75
16.0
35.3
68.0
119
192 160
140 x(m) 2.16 0 − ( − 5.00 m ) 2 120
100
80
60
40
20 (b) We will use a 0.400 s interval
centered at t = 4.00 s . We find at
t = 3.80 s , x = 60.2 m and at
t = 4.20 s , x = 76.6 m . Therefore,
∆x 16.4 m
v=
=
= 41.0 m s .
∆t 0.400 s 0
0.00 1.00 2.00 3.00
t(s) 4.00 5.00 6.00 Using a time interval of 0.200 s, we find the corresponding values to be: at t = 3.90 s ,
∆x 8.20 m
=
= 41.0 m s .
x = 64.0 m and at t = 4.10 s , x = 72 .2 m . Thus, v =
∆t 0.200 s
For a time interval of 0.100 s, the values are: at t = 3.95 s , x = 66.0 m , and at
∆x 4.10 m
=
= 41.0 m s .
t = 4.05 s , x = 70.1 m . Therefore, v =
∆t 0.100 s ∆x 68.0 m
=
= 17.0 m s . This
4.00 s
∆t
value is m u ch le ss than the instantaneous velocity at t = 4.00 s . (c) At t = 4.00 s , x = 68.0 m . Thus, for the first 4.00 s, v = 2.17 (a) v 0.50 s = (b) v 2.0 s = (c) v 3.0 s = (d) v 4.5 s = x 1.0 s − x t = 0
1.0 s − 0 x 2.5 s − x 1.0 s
2 .5 s − 1.0 s
x 4.0 s − x 2.5 s
4.0 s − 2 .5 s
x 5.0 s − x 4.0 s
5.0 s − 4.0 s = = 4.0 m
= 4.0 m s
1.0 s − 6.0 m
= − 4.0 m s
1.5 s x(m)
4
3
2
1
–1
–2 = 0
=0
1.5 s = +2.0 m
= 2.0 m s
1.0 s
26 1 2 3 4 5 t(s) CHAPTER 2.18 2 (a) The average speed during a time interval ∆t is v = d istan ce tr a v eled
.
∆t During the first quarter mile segment, Secretariat’s average speed was 0.250 m i 1320 ft
=
= 52 .4 ft s
25 .2 s
25 .2 s v1 = ( 35.6 mi h ) . During the second quarter mile segment, v2 = 1320 ft
= 55.0 ft s
24.0 s ( 37.4 mi h ) . For the third quarter mile of the race, v3 = 1320 ft
= 55.5 ft s
23.8 s ( 37.7 mi h ) , and during the...
View
Full
Document
This note was uploaded on 03/03/2010 for the course PHY P221 taught by Professor Dr.ha during the Spring '05 term at Indiana University South Bend.
 Spring '05
 Dr.Ha
 Physics, Acceleration

Click to edit the document details