School Work

SJPO_General_Round_2011.pdf

Categories
Published
of 21
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Related Documents
Share
Description
SJPO_General_Round_2011.pdf
Transcript
  SINGAPORE JUNIOR PHYSICS OLYMPIAD 2011GENERAL ROUND 3 August, 20112:30 pm – 4:00 pmTime Allowed: ONE hour THIRTY minutes INSTRUCTIONS 1. This paper contains  50  multiple choice questions and  21  printed pages.2. Each of the questions or incomplete statements is followed by five suggested an-swers or completions. Select the one that is best in each case and then shade thecorresponding bubble on the answer sheet.3. Only the answer sheet will be collected at the end of the test. Answers writtenanywhere else will not be marked.4. Use 2B pencil only. Using any other type of pencil or pen may result in answersunrecognizable by the machine.5. Answer all questions. Marks will  NOT  be deducted for wrong answers.6. Scientific calculators are allowed in this test.7. A table of information is given in page 2.  TABLE OF INFORMATIONAcceleration due to gravity at Earth surface,  g  = 9 . 80 m/s 2 Universal gas constant,  R  = 8 . 31 J / (mol · K)Vacuum permittivity,   0  = 8 . 85 × 10 − 12 C 2 / (N · m 2 )Vacuum permeability,  µ 0  = 4 π × 10 − 7 T · m / AAtomic mass unit,  u  = 1 . 66 × 10 − 27 kgSpeed of light in vacuum,  c  = 3 . 00 × 10 8 m / sCharge of electron,  e  = 1 . 60 × 10 − 19 CPlanck’s constant,  h  = 6 . 63 × 10 − 34 J · sMass of electron,  m e  = 9 . 11 × 10 − 31 kgMass of proton,  m  p  = 1 . 67 × 10 − 27 kgBoltzmann constant,  k  = 1 . 38 × 10 − 23 J/KAvogadro’s number,  N  A  = 6 . 02 × 10 23 mol − 1 Standard atmosphere pressure,  P  0  = 1 . 01 × 10 5 PaDensity of water,  ρ w  = 1000 kg / m 3 Lorentz Transformation:  x  =  x − ut   1 − u 2 /c 2 y  =  yz   =  z t  =  t − ux/c 2   1 − u 2 /c 2 2  1. A car accelerates from 4.0 m/s to 24 m/s at a rate of 3.0 m/s 2 . How far does ittravel while accelerating?(A) 56 m(B) 93 m(C) 158 m(D) 195 m(E) 279 m2. A marathon runner runs at a steady speed of 15 km/hr. When the runner is 7.5km from the finish, a bird begins flying from the runner to the finish at 30 km/hr.When the bird reaches the finish line, it turns around and flies back to the runner,and then turns around again, repeating the back-and-forth trips until the runnerreaches the finish line. How many kilometers does the bird travel?(A) 10 km(B) 15 km(C) 20 km(D) 30 km(E) 45 km3. A 2 kg mass and a 4 kg mass on a horizontal frictionless surface are connected bya massless string A. They are pulled horizontally across the surface by a secondstring B with a constant acceleration of 12 m/s 2 . What is the magnitude of thenet force on the 2 kg mass?(A) 72 N(B) 48 N(C) 24 N(D) 6 N(E) 3 N3  4. Superman stands on the roof garden of a very tall building on Earth with oneball in each hand. If the red ball is thrown horizontally off the roof and the blueball is simultaneously dropped over the edge, which statement is true? Neglect airresistance.(A) Both balls always hit the ground at the same time with the same speed.(B) The red ball strikes the ground first with a higher speed than the blue ball.(C) The blue ball strikes the ground first, but with a lower speed than the redball.(D) Both balls always hit the ground at the same time, but the red ball has ahigher speed just before it strikes the ground.(E) If the initial speed of the red ball is high enough, it may strike the groundlater with a higher speed than the blue ball.5. A drum has a radius of 0.40 m and a moment of inertia of 4.5 kgm 2 . The frictionaltorque of the drum axle is 3.0 N m. A 15 m length of rope is wound around therim. The drum is initially at rest. A constant force is applied to the free end of the rope until the rope is completely unwound and slips off. At that instant, theangular velocity of the drum is 13 rad/s. The drum then decelerates and comes toa halt. The constant force applied to the rope is closest to(A) 7.5 N(B) 14 N(C) 18 N(D) 27 N(E) 33 N6. A tether ball is on a 2.1 m string which makes an angle of 22 ◦ with the vertical asit moves around the pole in a horizontal plane. If the mass of the ball is 1.3 kg,what is the ball’s speed?(A) 1.4 m/s(B) 1.6 m/s(C) 1.8 m/s(D) 2.0 m/s(E) 2.2 m/s4
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks