• Chapters 2 thru 5
• Chapters 6 thru 9
• Chapters 10 thru 14
• Chapters 15 thru 18

Chapter 2

Review Questions

10. 70 pounds to the right

13. 0 Newtons

14. 0 Newtons

21. 100 N opposite the motion

 

Exercises

26. Staging weighs 400 N - 250 N = 150 N

27. Right-Hand Scale reads 250 N + 300 N + 300 N - 400 N = 450 N

28. The scale reads half of Nellie's weight

 

Chapter 3

Review Questions

  5. 30 km/hr

11. 10 km/hr/s = 10 km/(hr s)

12. 0

19. 10 m/s

20. 50 m/s; 60 m/s

22. 10 m/s

24. 5 m; 80 m

One-Step Calculations

  3. 50 m/10 s = 5 m/s

17. v = 10(m/s^2) * 7 s = 70 m/s

19. v = 20(m/s^2) * 1.5 s = 30 m/s

20. d = (1/2) * (10 m/s^2) * (1.5 s)^2 = 11.25 m

20. 50 m/s; 60 m/s

22. 10 m/s

24. 5 m; 80 m

Problems

  1. t = 3 m/[1.5 X 10^(-3) m/yr] = 2 X 10^3 yr

  3. time in air = 3 s up and 3 s down; max height = 45 m

  6. a = (25 m/s - 0 m/s)/10 s = 2.5 m/s^2

  9. v^2 = 2 * (10 m/s^2) * (1 x 10^3 m)

  9. (cont.) v = 141 m/s = 315 mph

 

Chapter 4

One-Step Calculations

  1. F_g = (50 kg) * (10 m/s^2) = 500 N

  5. m = (300 N)/(10 m/s^2) = 30 kg

  8. a = F_net/m (a) a = 20 N/2 kg = 10 m/s^2; (b) a = (20 N - 4 N)/2 kg = 8 m/s^2

  9. a = 10 m/s^2 ==> F_net = m * a = 1 kg * 10 m/s^2 = 10 N

Exercises

  7. F_f = F_g = (400 kg) * (10 m/s^2) = 4000 N

14. moon: F_g = (10 kg) * (10/6 m/s^2) = 16.7 N; earth: F_g = (10 kg) * (10 m/s^2) = 100 N; m = 10 kg everywhere

27. a = F_net/m = 30 N/(3 * block_mass) = 10 N/(block_mass) ==> 10 N in left string; 20 N in center string

Problems

  1. a = F_net/m = (0.9 * m * g)/m = 0.9 g = 9 m/s^2

  3. a = F_net/m = (300 N up + 200 N down)/20 kg = 100 N/20 kg = 5 m/s^2

  5. a = F_net/m = 4 * (30,000 N)/30,000 kg = 4 m/s^2

 

  3. R = sqrt[ (4 units)^2 + (3 units)^2] = sqrt[25 units^2] = 5 units

22. a_left-block = F/m; a_right-block = F/2m ==> larger block is half as fast

  2. F_wall = 40 N; a = F_wall/m = 40 N/80 kg = 0.5 m/s^2

  3. v_relative = sqrt[(4 m/s)^2 + (3 m/s)^2] = sqrt(25 m^2/s^2) = 5 m/s

 

Chapter 6

One-Step Calculations

  1. p = (8kg) * (2 m/s) = 16 kg m/s

  3. J = (10 N) * (2.5 s) = 25 kg m/s

  5. J = 0 - (8kg) * (2 m/s) = -16 kg m/s

  3. v = P_0 /(m1 + m2) = (6 kg m/s)/(4 kg) = 1.5 m/s

Problems

  1. F = (p - p_0)/t = (0 - 200 kg m/s)/(3 s) = -66.7 N

  2. F = (0 - 16 kg m/s)/(0.5 s) = -32 N; F = -32 N

  7. v = P_0/(m + 4m) = [(4m) * (5 km/hr)]/(5m) = 4 km/hr

  8. v2 = -p1/m2 = (-5 kg m/s)/(1 kg) = -5 m/s

Chapter 7

Review Questions

10. K.E. = (m/2)*(4 * v0^2) = 16 (m * v0^2)/2 = 16 * K.E._0

11. 16 times as much; 16 times as far

12. K.E. = F_net * d = (30 N) * (10 m) = 300 J

One-Step Calculations

  3. W = (500 N) * (2.2 m) = 1100 J

  6. P = W/t = 1100 J/2 s = 550 Watts

  8. P.E. - P.E._0 = (20 kg) * (10 m/s^2) * (2 m) = 400 J

11. K.E. = (3 kg)/2 * (4 m/s)^2 = 24 J

12. K.E. = (3 kg)/2 * (8 m/s)^2 = 4 * 24 J = 96 J

13. W = K.E. - K.E._0 = 5000 J

Problems

  2. K.E. = K.E._0 - (P.E - P.E._0) = 0 - (1000 J - 10,000 J) = +9,000 J

  4. 3 times the speed --> 9 times the K.E. ---> d = 9 * 15 m = 135 m

  8. Since K.E. of skydiver doesn't increase, all of
the work done by gravity is turned into heat due to air friction:
Work = mgh =30,000 J = 30 kJ, so Power = 30 kJ/1s = 30 kiloWatts

  9. K.E. = (1/2) * (2*m) * (v0/2)^2 = (1/2) * [(1/2) * m * v0^2] = K.E._0 / 2;
the rest goes into heat and sound.

Chapter 8

Review Questions

32. Increase in L = 0; angular speed doubles

One-Step Calculations

  1. torque = (0.2 m) * (50 N) = 10 Nm

  2. torque = (0.5 m) * (50 N) = 25 Nm

  3. F_tension = (2 kg) * (3 m/s)^2 /(2.5 m) = 7.2 N

  4. F_friction = (75 kg) * (3 m/s)^2 /(2 m) = 337.5 N

Problems

  2. v = r * omega = (10 m) * (2*pi rad/30 sec) = 2.1 m/s

  4. F_right * L = (10,000 N) * (L/4) => F_right = 2.500 N; F_left = 10,000 N - F_right = 7,500 N

  5. Fg_rock * L/4 = Fg_stick * L/4 => m_rock = m_stick = 1 kg

Chapter 9

One-Step Calculations

  1. 10 N

  2. 2.5 N

  3. 2.1 x 10^20 N

  4. 3.6 x 10^22 N

Problems

  2. 10/16 m/s^2

  4. 3.1 x 10^12 m/s^2

  5. 0.94 * g or 94% of g

Chapter 10

Problems

  1. 14.1 m/s

  9. 1 km/s

Chapter 11

Problems

  1. 16 g Oxygen

  2. 4 g of Hydrogen

Chapter 12

Problems

  1. 18 g/cm^3

  3. 9 cm

  9. Volume = 8 cm^3; Surface area = 24 cm^2, while the total surface area of the 8 small cubes is 48 cm^2

Chapter 13

One-Step Calculations

  1. 1 x 10^6 N/m^2

Problems

  1. 2.2 x 10^6 N/m^2

  2. 6000 kg/m^3

Chapter 14

Problems

  7. a) 20,000 N; b) 1.7 x 10^3 m^3

  8. F = 400,000 N

Return to top of document

Chapter 15

Problems

  2. 2 megacalories or 8.4 megajoules

Chapter 16

Problems

  6. area = 150 m^2

Chapter 17

Problems

  1. a) 80 kcal; b) 100 kcal; c) 540 kcal; d) 720 kcal

Chapter 18

Problems

  1. W = 3000 Joules

  3. %e = 7%

  5. T = 65 degrees Celsius

Return to top of document

Page last modified March 31, 2006

Return to Gibson Home Page