Exam 2 Study Oct. 30 PDF

1. A spring scale hung from the ceiling stretches by 23 cm when a 2.3 kg mass is hung from it. The 2.3 kg mass is removed and replaced with a 3.5 kg mass. What is the stretch of the spring? Round to two decimal places and express in terms of cm. 2. 53 g tennis ball is served at 36 m/s. If th...

1. A spring scale hung from the ceiling stretches by 23 cm when a 2.3 kg mass is hung from it. The 2.3 kg mass is removed and replaced with a 3.5 kg mass. What is the stretch of the spring? Round to two decimal places and express in terms of cm. 2. 53 g tennis ball is served at 36 m/s. If the ball started from rest, what impulse was applied to the ball by the racket? Include three decimal places and express the answer in terms of SI units. 3. The New England Merchants Bank Building in Boston is 152 m high. On windy days it sways with a frequency of 0.15 Hz, and the acceleration of the top of the building can reach 3.5 % of the free-fall acceleration, enough to cause discomfort for occupants. What is the total distance, side to side, that the top of the building moves during such an oscillation? Include three decimal places and express the answer in terms of SI units 4. Some passengers on an ocean cruise may su er from motion sickness as the ship rocks back and forth on the waves. At one position on the ship, passengers experience a vertical motion of amplitude 1.36 m with a period of 17 s. What is the maximum acceleration of the passengers during this motion? Include three decimal places amd express in terms of SI units. 5. As part of a safety investigation, a 1304 kg car traveling at 4.9 m/s is crashed into di erent barriers. Find the average forces exerted on the car that hits a brick wall and takes 0.17 s to stop. Round to two decimal places and express the answer in terms of SI units. 6. Zach, whose mass is 63.6 kg, is in an elevator descending at 5.4 m/s. The elevator takes 4.2 s to brake to a stop at the rst oor. What is Zach’s apparent weight while the elevator is braking? Round to two decimal places and express the answer in SI units. 7. A 64 kg student is walking on a slackline, a length of webbing stretched between two trees. The line stretches and so has a noticeable sag of θ=27°, as shown in the gure below. At the point where his foot touches the line, the rope applies a tension force in each direction, as shown. What is the tension in the line? Round to two decimal places and express in terms of SI units. 8. In a head-on collision, a car stops in 0.11 s from a speed of 10.3 m/s. The driver has a mass of 73 kg, and is, fortunately, tightly strapped into his seat. What is the magnitude of the average force applied to the driver by his seat belt during that fraction of a second? Round to two decimal places and express the answer in SI units. 9. A construction crew would like to support a 949 kg steel beam with two angled ropes as shown in the gure below. Their rope can support a maximum tension of 5398 N. What is the maximum value of θ such that the ropes will be able to support the beam without snapping. Round to two decimal places and express the answer in degrees. 10. The three ropes in the gure below are tied to a small, very light ring. The ropes labeled "Rope 1" and "Rope 2" are anchored to walls at right angles, and the third rope pulls at an angle θ=21 degrees with a magnitude of F=73 N. What is the Tension in rope 2? Round to two decimal places and express the answer SI units. 11. A compact car has a maximum acceleration of 3.2 m/s/s when it carries only the driver and has a total mass of 1366 kg. What is its maximum acceleration after picking up four passengers and their luggage, adding an additional 341 kg of mass? Round to two decimal places and express in SI units. 12. A constant force is applied to an object, causing the object to accelerate at 21.06 m/s/s. What will the acceleration be if the force is doubled? Round to two decimal places and use SI units. 13. A constant force is applied to an object, causing the object to accelerate at 22.22 m/s/s. What will the acceleration be if the mass is doubled? Round to two decimal places and use SI units. 14. A constant force is applied to an object, causing the object to accelerate at 1.48 m/s/s. What will the acceleration be if both the force and the mass are doubled? Round to two decimal places and use SI units. 15. In t-ball, young players use a bat to hit a stationary ball o a stand. The 146 g ball has about the same mass as a baseball, but it is larger and softer. In one hit, the ball leaves the bat at 9.4 m/s after being in contact with the bat for 1.4 ms. Assuming that the accelerationis constant during the hit, what is the net force on the ball? Round to two decimal places and use SI units.