Kolsawala (alk472) - 2-PHY317k-Homework - lang - (57345) is an avalanche, in which a large mass of snow 2. 1.215-44 and ice breaks loose and goes on an essentially 3. 1.36112 frictionless "ride" down a mountainside on a 4. 0.493908 cushion of compressed air. 5. 1.89677 The acceleration of gravity is 9.8 m/s. 6. 2.63454 7. 2.2349 8. 6.03611 9. 8.3215 avalanche 10. 0.273274 Answer in units of m/s . 3:3" 011 10.0 points A crate of mass 10 kg rests on a horizontal surface. The coefficient of static friction is for the crate on that surface. If you were on a 33" slope and an avalanche started 341 m up the slope, how much time constant horizontal force of 45 N is applied to would you have to get out of the way? the crate, and it remains at rest. 45 N 1. 10.1464 2. 13.9679 3. 10.8255 4. 12.3228 What is the magnitude of the force of static 5. 15.4663 friction acting on the crate? The acceleration 6. 14.5083 due to gravity is 10 m/s". 7. 9.7591 8. 11.8701 1. 45 N 9. 11.3038 2. Zero since it is not sliding; it is still at 10. 11.5897 rest. Answer in units of s. 3. f, is undefined in such a case. 4. 50 N (using As mg) 010 10.0 points 5.5 N A block is pushed up a frictionless incline by an applied horizontal force as shown. 012 10.0 points The acceleration of gravity is 9.8 m/s-. A block is released from rest on an inclined plane and moves 3 m during the next 3.2 s. The acceleration of gravity is 9.8 m/s. F = 37 N 2.6 kg il kg 30 What is the magnitude of the resulting ac- celeration of the block? What is the coefficient of kinetic friction fx 1. 1.14238 for the incline?kolsawala (af*472) - 2-PHY317k-Homework - lang - (57345) 1. 0.363083 force that increases uniformly from 0 to 247 2. 0.703297 N. 3. 0.658911 What is the equivalent spring constant of 4. 0.449609 the bow? 5. 0.508312 6. 0.545307 1. 423.8 7. 0.590089 2. 445.344 8. 0.685358 3. 472.222 9. 0.245444 4. 546.46 10. 0.280903 5. 735.119 6. 584.45 013 10.0 points 7. 489.362 A force F applied to a crate of mass M at 8. 645.669 an angle a makes the crate move horizontally 9. 624.665 with a constant acceleration of magnitude a. 10. 477.273 The coefficient of kinetic friction between the Answer in units of N/m. crate and the surface is fix. F 015 10.0 points A child's toy consists of a piece of plastic attached to a spring, as shown. The spring is M compressed against the floor a distance of 1.7 cm and released. Select the correct expression for | FI|, the magnitude of the force. 1. IF = Mo-piMg 4 sin a 2. IF = MM g - Ma If the spring constant is 77 N/m, what is cosa + /t sin a the magnitude of the spring force acting on 3. IF = Ma - uk Mg the toy at the moment it is released? cosa + /x sino 4. IF =- MMg - Ma 1. 1.35 308 0 - At sin a 2. 2.256 5. IF = 3. 1.032 4. 1.309 6. IF= Ma- ARMg 5. 2.07 COS C 6. 1.95 7. F= MatAMg 7. 1.848 Ma - UM g 8. 1.72 8. IIF = 9. 1.106 cosa - Ar sin a 10. 2.35 9. IF= MatiMg Answer in units of N. cosa + At sino 10. |F = MatuMg 016 10.0 points coS O - AR sin a A 25 kg child sits in a swing supported by two 014 10.0 points chains, each 3.7 m long. In preparing to shoot an arrow, an archer The acceleration of gravity is 9.8 m/s". pulls a bow string back 0.452 m by exerting a If the tension in each chain at the lowestkolsawala (afk472) - 2-PHY317K-Homework - lang - (57345) 5 point is 184 N, find the child's speed at the Answer in units of N. lowest point. Note: Neglect the mass of the seat. 018 10.0 points The Joule and the kilowatt-hour are both 1. 5.53385 units of energy. 2. 3.69574 19.7 kW . h is equivalent to how many 3. 5.67212 Joules? 1. 4.05298 5. 2.04939 1. 6.768 x 10 6. 2.26127 2. 5.76 x 10' 7. 1.40933 3. 5.04 x 105 8. 3.90128 4. 7.092 x 10 9. 2.67238 5. 6.84 x 10' 10. 4.26661 6. 4.932 x 10 Answer in units of m/s. 7. 2.628 x 10 8. 6.516 x 10 017 10.0 points 9. 4.68 x 10" A small ball of mass 83 g is suspended from a 10. 3.744 x 10 string of length 77 cm and whirled in a circle Answer in units of J. lying in the horizontal plane. 019 10.0 points Lee pushes horizontally with a force of 61 N on a 21 kg mass for 11 m across a floor. Calculate the amount of work Lee did. 1. 671 9.8 m/8- 219 2. 1725 3. 1189 W LL 4. 2300 5. 2250 B. 1159 7. 2418 8. 1649 83 g 9. 826 If the string makes an angle of 21" with the 10. 1326 vertical, find the centripetal force experienced Answer in units of J. by the ball. The acceleration of gravity is 9.8 m/8 . 020 10.0 points A 4.4 x 10" kg car accelerates from rest at 1. 0.542035 the top of a driveway that is sloped at an 2. 0.424435 angle of 16.3" with the horizontal. An average 3. 0.242 frictional force of 4.3 x 10* N impedes the car's 4. 0.222722 motion so that the car's speed at the bottom 5. 0.370876 of the driveway is 4.7 m/s. 6. 0.195971 The acceleration of gravity is 9.81 m/s. 7. 0.356351 What is the length of the driveway? 8. 0.150475 9. 0.312235 1. 4.36703 10. 0.177166 2. 4.27083kolsawala (afk472) - 2-PHY317K-Homework - lang - (57345) 6 3. 6.21879 m which moves with constant speed v across 4. 6.99776 a horizontal floor. The coefficient of friction 5. 7.3286 between the box and the floor is a. 6. 3.91783 At what rate does the child do work on the 7. 3.74012 box 8. 7.89202 9. 3.44352 1. P= 10. 3.70223 Answer in units of m. 2. P= 3. P= umu 021 (part 1 of 2) 10.0 points A. P = umgu A 4.04 g bullet moving at 661.8 m/s pene- 5. P= mgv trates a tree trunk to a depth of 3.84 cm. a) Use work and energy considerations to 024 10.0 points find the magnitude of the force that stops the As a freely falling object picks up downward bullet. speed, what happens to the power supplied by the gravitational force? 1. 21937.8 2. 18677.9 1. Unable to determine 3. 29706.8 2. The power decreases. 4. 17747.1 3. The power stays the same. 5. 15048.6 4. The power increases. 6. 14360.1 7. 24064.5 025 10.0 points 8. 12992.8 A car with a mass of 1250 kg kg starts from 9. 32870.7 rest and accelerates to a speed of 14.1 m/s 10. 23039.5 in 19 s. Assume that the force of resistance Answer in units of N. remains constant at 360.1 N during this time. What is the average power developed by 022 (part 2 of 2) 10.0 points the car's engine? b) Assuming that the frictional force is con- stant, determine how much time elapses be- 1. 19827.6 tween the moment the bullet enters the tree 2. 14737.6 and the moment the bullets stops moving. 3. 9846.55 4. 9078.51 1. 0.000118743 5. 8472.73 2. 0.000162466 6. 22651 3. 0.000152054 7. 9701.37 4. 9.69926 x 10-5 8. 27299.6 5. 0.000141138 9. 12856.1 6. 9.51542 x 10-5 10. 24094.9 7. 0.000166032 Answer in units of W. 8. 0.000116047 9. 0.000145105 10. 8.96641 x 10-5 Answer in units of s. 023 10.0 points A child pushes horizontally on a box of mass