DW's Homework Answers
Click Here to send me a note if you think there is an error here.
Chapter 17:
- 2: separation distance is 0.70 m.
Chapter 16:
- 2: f = 5.5 x 1014 Hz.
- 6: f = 0.2 Hz, v = 4.0 m/s.
- 40: Distance = 7.58 km
- 54: 800 seconds
- 74: 0.031
- 86: a) 194 m/s
b) 2.59 x 10-4 Hz.
c) 3866 seconds
- 94: 123 dB
- 100: 79,400 people
Chapter 14:
- 2: 1.29 x 1021 molecules of Tyelenol.
5.84 x 1020 molecules of Advil.
- 10: temperature = 304K, or 31oC
- 22: Vtop/Vbottom = 1.02
Chapter 13:
- 12: 3.1 x 10-5kg/s of ice melts.
- 18: filament area = 2.56 x 10-5 m2
- 20: temperature = 5798K
Chapter 12:
- 56: Q=3.94 x 105J, from evaporation of 0.163 kg of sweat.
- 80: final temperature = 63.9oC
Chapter 11:
- 1: so it would be a square 17.8 m on a side
- 24: max depth = 0.5 m
- 50: 8.13 x 106gal/day
- 58: P1-P2=96 N/m2
Chapter 10:
- 2: x=0.218 m
- 24: energy= 46.9 J, v=56 m/s
- 40: This is just 1/4 of a period, and T=1.62 s, so T/4=0.405 s
- 52: Stress = F/A = 1.7 x 108N/m2,
Strain=delta L/Lo=F/AY= 1.81 x 10-2
- 58:(a) Strain = 2.5 x 10-4 (b) 7.46 x 10-5m
Chapter 9:
- 2: 210 N
- 6a: 13,500 Nm, 6b: 82,500 Nm
- 12: 0.7 m
- 18: 1200 N
- 34: torque=8 x 10-4Nm
- 48: 7.67 m/s
- 52: 7.1 rad/s
Chapter 8:
- 2: 20.7 radians (note that 330 rev/min = 5.5 rev/s=34.6 rad/s)
- 6: 8.0 seconds
- 18: 5.22 seconds
- 20: It has rotated through an angle of 4,600 radians, while undergoing an angular acceleration of 200 rad/s
- 36: 6.53 rad/s2
Chapter 7:
- 12: total momentum = 322 kg m/s at 15.7 degrees north of east.
Chapter 6:
- 8: Work by push = 1050 J, work by friction = -943 J
- 14: v = 39.5 m/s
- 60: power = 4,000 W on the flat, and power = 33,400 W on the hill.
Chapter 5:
- 2: 0.792 m/s2
- 10: 10,570 revolutions per minute. Note it is going 0.3142 m/rev and 3320 m/min
- 20: 23o
- 30: T = time for one orbit = 2.38 x 106sec = 27.5 days
- 52: at equator ac=0.0337 m/s2, at 30o latitude ac= 0.0292 m/s2
Chapter 4:
- 14: 1.39 MN
- 20: a=4.24 m/s2
- 30: Fsun/Fmoon=178
- 50: 4,257 N
- 58: T1=919 N, T2=845 N
Chapter 3:
- 6: vx=10.7 m/s, vy=13.2 m/s
- 14: vhorizontal=constant=8.6 m/s
- 26: 0.842 m
Chapter 2:
- 2: (a) 7.07 km (b) 2.12 km NE
- 6: el-Guerrouj wins by 109 meters
- 16: a) north, b) 7.13 m/s
- 28: 96.9 m/s
- 44: a) final v = 7.88 m/s downward, b) 3.165 m above the water.
- 68: 1.08 s
Math Review Sheet
- 1a: x8, 104, 5x10-5, 10, 3 x 10-6
- 1b: 3.26 x 104, 8.31 x 10-1, 2 x 10-4, 1.006 x 103, 1.9 x 10-10
- 2a: angle=65 degrees, sides are 9.06 cm and 4.23 cm long
- 2b: AC = 31.8 m long, side AD = 24.7 m long
- 3: 120, -2 and 3/2, -50, 99.99, 4.1 x 10-18, 0.0623
- 4: 0.00358 g, 0.0000023 g, 15.7 MN
back to the class page