SAMPLE QUIZ 3 - PHYSICS 1301.1 his is a closed book, closed notes quiz. Calculatos ae pemitted. he ONLY fomulas that may be used ae those given below. Define all symbols and justify all mathematical expessions used. Make sue to state all of the assumptions used to solve a poblem. Cedit is given only fo a logical and complete solution that is clealy communicated. Patial cedit will be given fo a well communicated poblem solving stategy based on coect physics such as the stategy illustated in the Competent Poblem Solve. MAKE SURE YOUR NAME, ID #, and A s NAME ARE ON EACH PAGE!! Each poblem is woth 25 points: In the context of a unified solution, a useful pictue, defining the question, and giving you appoach is woth 6 points; a complete physics desciption giving a diagam, defining the elevant quantities, identifying the taget quantity, and specifying the elevant equations is woth 7 points; planning the solution by constucting the mathematics leading to an algebaic answe is woth 7 points; calculating an answe is woth 3 points; and evaluating the validity of the answe is woth 2 points. he 10 multiple choice questions ae woth 25 points. Useful Mathematical Relationships: If Ax 2 + Bx + C = 0, then x = d(z n ) d w = nz n 1, d(cosz) = w, z n v x = x t vx = dx θ c b s = dist t s= d a Fo a ight tiangle: sin θ = a c, cos θ = b c, tan θ = a b, B ± = sin z, d(sinz) = zn+1 (n 1) n +1 a x = v x t a x = dv x a 2 + b 2 = c 2, sin 2 θ + cos 2 θ = 1 Fo a cicle: C = 2πR, A = πr 2 Fo a sphee: A = 4πR 2, V = 4 3 πr3 B 2 4AC 2A = cosz, df(z) = df(z), dw = w,, p f p i = p tansfe dθ = v Ef Ei = E tansfe F = m a KE = 1 2 mv2 p = m v W = F d l p tansfe = path F Unde Cetain Conditions: x = a x 2 ( t)2 + v xo t + x o a = v2 F = µ k F N F µ s F N F = kx PE = mgh PE = 1 2 kx2 Useful constants: 1 mile = 5280 ft, g = 9.8 m/s 2 = 32 ft/s 2
Pat 1 - Poblems 1. You have a job at a company that designs equipment fo spots shows and exhibitions. he company has been given the contact to design an appaatus fo an ice skating show. An ice skate will stat fom est and glide down an ice-coveed amp. At the bottom of the amp, the skate will continue gliding aound an ice-coveed loop inside of a vetical cicle. Afte going aound the vetical cicle, the skate emeges at the bottom of the cicle to glide out on the skating ink floo. o make a spectacula effect, the cicula loop should have a diamete of 30 feet. You task is to detemine the minimum height fom the top of the amp to the ink floo so that the skate will not fall off the loop at the top. 2. You have a job in a eseach goup investigating the effects of nomal envionmental adiation on DNA molecules in ou body. o test this idea, you eseach goup decides to detemine the enegy deposited in a nucleus of an atom in DNA afte a neuton fom the envionment knocks out one of the neutons in the nucleus. In an expeiment, a neuton with an enegy of 2.1 MeV, hits a nucleus of one of the atoms of the DNA molecule and knocks out only one othe neuton. he two emeging neutons ae detected at 30 o and 15 o fom the diection of the incoming neuton. he nucleus, still in the atom attached to the DNA molecule, emains stationay. he mass of a neuton is 1.7 x 10-27 kg. 3. You ae supplying technical advice fo a developing county. You have been asked to devise a vey inexpensive test instument to check the quality of spings that ae manufactued fo engine contols. You decide to clamp one end of sping to be tested so that it is held hoizontally on a table top. It is then compessed by a specified amount and used to shoot a mable ove the edge of the table onto the floo. You detemine an equation that uses whee the mable hits to detemine the sping constant as long as you know the mass of the mable and the height of the table as well as the amount the sping was compessed.
Conceptual Questions he figue depicts two pucks on a fictionless table. Puck I is thee times moe massive than puck II. Stating fom est, both pucks ae simultaneously and continuously pushed acoss the table by equal foces. he next two questions efe to this situation. 1. Which puck will have the geate enegy at the instant the fist puck eaches the finish line? (a) puck I (b) puck II (c) hey will both have the same enegy. (d) oo little infomation to answe. 2. Which puck will have the geate momentum at the instant the fist puck eaches the finish line? (a) puck I (b) puck II (c) hey will both have the same momentum. (d) oo little infomation to answe. 3. Suppose you ae pushing hoizontally on a lage box that moves acoss the floo at a constant speed. What do you know about the foces on the box? (a) If the foce you apply to the box is doubled, its speed will double. (b) he foce you apply equals the fictional foce on the box. (c) he foce you apply is geate than the fictional foce on the box. (d) he foce you apply is geate than the weight of the box. (e) he foce you apply is geate than the foce that the box applies on you. 4. An object on a vetical sping is moving up and down. When the object is at its lowest point, which of the following statements is not tue? (a) Its velocity is zeo. (b) Its acceleation is zeo. (c) he sping s foce on the object is maximum. (d) Its acceleation is up. (e) It s at its maximum displacement fom its equilibium position.
Questions 5 and 6 efe to a 16-lb bowling ball hits uns into a 2-lb bowling pin. 5. Compae the elative sizes (magnitudes) of the foces on the ball and pin. (a) he ball exets a geate foce on the pin. (b) he pin exets a geate foce on the ball. (c) hey exet equal size (magnitude) foces on each othe. (d) Only the ball exets a foce on the pin. (e) Only the pin exets a foce on the ball. 6. Duing the impact of the bowling ball and pin, how does the acceleation of the ball and pin compae? (a) he ball acceleates less than the pin. (b) he ball and the pin have the same acceleation. (c) he ball and the pin have equal acceleations, but in opposite diections. (d) he ball acceleates moe than the pin. (e) It is impossible to tell without knowing the velocity of the ball. 7. In ode to stat a ca with a dead battey, you ae pushing it along a oad at a steadily inceasing speed: (a) the size of the foce that you ae exeting on the ca is equal to that of the ca pushing back against you. (b) the size of the foce that you ae exeting on the ca is less than that of the ca pushing back against you. (c) the size of the foce that you ae exeting on the ca is geate than that of the ca pushing back against you. (d) whethe the size of the foce that you ae exeting on the ca is geate o less than that of the ca pushing back against you depends on the weight of the ca. (e) whethe the size of the foce that you ae exeting on the ca is geate o less than that of the ca pushing back against you depends on the fictional foce.
8. Suppose you attach a ball to a sting that you hold in you hand at point O and otate at a high constant speed in a vetical plane in font of you. he cicle shows the path of the ball. Which fee-body diagam shown below epesents the foces acting on the ball when it is at the bottom of the cicula path and moving towads the ight? Ignoe ai esistance. O F W W W W F c W (a) (b) (c) (d) (e) 9. A sping is attached to a wall. he othe end of the sping is attached to a book. he book is pulled a distance x fom the sping s equilibium position and eleased fom est. Conside the time inteval while the book is moving back to the equilibium position. Which of the following esult in an enegy input to the system defined as the physics book? x (a) he foce (pull) of the sping on the book. (b) he fictional foce of the floo on the book. (c) he nomal foce of the floo on the book. (d) he gavitational foce of the eath on the book. (e) Can t tell since enegy is not conseved in this system. 10. You slam on the bakes of you ca in a panic and skid a cetain distance on a staight and level oad. If you had been taveling twice as fast, you would have skidded (a) eight times futhe. (b) fou times futhe. (c) twice as fa. (d) the squae oot of two times futhe. (e) It is impossible to tell with the infomation given.