Clearly communicate your understanding of the physics principles that you are going to solve a question and how those principles apply to the problem at hand. You may communicate this understanding through calculation, graphically, and with diagrams but written statements are required. Vector calculations must be supported with suitable diagrams. Graphs must include complete supporting explanations. 1. The biomechanics lab at a local university runs a series of tests on potential Olympic athletes. The intent is to develop an appropriate training program for each athlete. The areas of study are energy output, impulse, efficient energy conversion and performance techniques. (10.00 marks) The trainer designs an exercise that requires the shot putter to throw the shot horizontally using arm motion only. The arm extension is 0.750 m; the hand at the point of release is 1.50 m above the ground. The shot lands 4.43 m horizontally from the hand. The mass of the shot is 7.26 kg. a) Calculate the speed the shot put leaves the hand. b) Using the speed calculated in part a, and any other given information, find the total mechanical energy of the shot immediately on release. ( If you were unable to calculate the answer to part a, use the hypothetical value v = 10.2 m/s) c) Find the impulse produced on the shot ball by the shot putter. (If you were unable to calculate the answer to part a, use the hypothetical value v = 10.2 m/s) d) If the action of pushing the shot takes 1.02 x 10-1 s, calculate the average force exerted by the shot putter. 2. A ballistics pendulum is being used by police investigators to measure the muzzle velocity of projectiles fired from a gun. The projectile strikes the pendulum and becomes imbedded its soft surface. The bullet of mass 0.066 kg raised the 0.285 m long pendulum (initial mass = 5.42 kg) through an angle of 47.8 o. (10.00 marks) State the two physics principles to be used in solving this problem. One investigator suggests that the initial kinetic energy of the bullet should be equal to the potential energy of the pendulum after it rises up. What is wrong with this notion? What was the initial velocity of the bullet?
3. An experiment was performed on the surface of an asteroid. A mass was dropped from various heights and the time taken to fall was recorded. (10.00 marks) a) Sketch a graph of the relationship of distance as a function of time. b) Use your graphing calculator to graph distance as a function of time 2. b) From your straight line graph, determine the slope of the line. (Include units.) c) What is the acceleration due to gravity on the surface of this asteroid?
Choose the best response and place your answers, using HB pencil, on the LXR 20020 sheet provided. You must include your student number and the version number of the test. 1. A skateboarder rolling east at 1.40 m/s has a momentum of 70.0 kg m/s [E]. The mass of the skateboarder is a. 71.4 kg. b. 98.0 kg. c. 50.0 kg. d. 0.0200 kg. 2. A 140 kg ostrich can reach a maximum momentum of 3.1 x 10 3 kg m/s for short distances. The velocity of the ostrich at that momentum, expressed in scientific notation, is a.bc x 10 d m/s. The values of a, b, c, and d are,,, and. (Record your four-digit answer in the numerical-response section on the answer sheet.) 3. A particular rocket consists of stage 1 (m = 4.500 0 x 10 4 kg) and stage 2 (m = 1.200 00 x 10 5 kg). Initially, the stages move together at 2.500 0 x 10 4 km/h. Later a small explosion causes the stages to separate. After separation, stage 1 moves 3.000 0 x 10 1 km/h slower than it did before separation. The speed, v 2, of stage 2 immediately after separation is: a. 24 920 km/h b. 24 989 km/h c. 25 011 km/h d. 25 080 km/h 4. A 1280 kg car is sitting in an intersection waiting to make a left turn when it is hit broadside by a 1640 kg SUV running a red light at 8.35 m/s [N]. After the 0.245 s collision, the vehicles remain locked together and skid down the street. The velocity of the combined wreck immediately after the collision would be a. 4.69 m/s [N]. b. 4.18 m/s [N]. c. 4.86 m/s [N]. d. 4.35 m/s [N].
5. Based on the information in the above narrative, the collision would be inelastic with a loss of kinetic energy of a. 43.8%. b. 56.2%. c. 24.6%. d. 75.4%. 6. Use the information from the above to calculate the impulse given to the car by the collision. The correct answer is a. 6.00 x 10 3 N s [N]. b. 1.37 x 10 4 N s [N]. c. 7.69 x 10 3 N s [N]. d. 6.06 x 10 3 N s [N] 7. Based on the information in the above narrative, calculate the average net force on the SUV during the collision. The correct average net force is a. 2.45 x 10 4 N [S]. b. 5.59 x 10 4 N [S]. c. 3.14 x 10 4 N [S]. d. 4.67 x 10 4 N [S]. 8. Use the following information to answer the next two questions. As a child catches a ball, he exerts a force, F, on the moving ball for a time interval, t. The mass of the ball is 250 g and its velocity changes from +5.00 m/s to +1.00 m/s as a result of the force, The magnitude of the impulse that the child applies to the ball is a. 1.00 N.s b. 1.25 N. c. 2.50 x 10 2 N. d. 1.00 x 10 3 N.s 9. If, when catching the ball, the child had applied triple the force, then the length of time that it would have taken to slow the ball would have been a. 9t b. 3t c. t d. 1/9t 10. In archery class, a student pulls back a 0.250 kg arrow with a bowstring. The average force exerted on the arrow is 195 N and the bowstring is drawn back 0.950 m. Assuming friction is negligible and the arrow is shot vertically up, what maximum height does it reach? a. 70.5 m b. 75.5 m c. 80.5 m d. 85.5 m Use the following information to answer the next two questions. A mountain biker glides down a hill that is 10 m above a depression. After passing through the depression, she coasts up a second, smaller hill that is 3.0 m above the depression. The rider and bike have a combined mass of 70.0 kg. 11. If the biker has a speed of 6.0 m/s at the top of the first hill, then the maximum speed that she could have at the top of the second hill, without pedaling, is a. 12 m/s b. 13 m/s c. 14 m/s d. 15 m/s 12. A day later, when the ground is muddy after a rain. The biker glides down the same hill. She has the same initial speed at the top of the first hill. She glides from the top of the first hill to the top of the second, but her speed at the top of the second hill is only 10 m/s. The work done on the bike and rider by the mud is a. -5.6 x 10 3 J b. -2.4 x 10 3 J c. -3.4 x10 3 J d. -1.0 x 10 4 J
13. As a 1250 kg car was passing through an intersection at 8.12 m/s [E] it was hit broadside by a pickup truck running a red light at 8.25 m/s [N]. Immediately after the 0.185 s collision, the velocity of the car was 5.65 m/s [73.1 o N of E], and the velocity of the truck was 6.47 m/s [38.5 o N of E]. The mass of the truck, expressed in scientific notation, was a.bc x 10 d kg. The values of a, b, c, and d, are,,, and. (Record your four digit answer on the numerical response section of your answer booklet.) 14. Based on the information above, the collision would be classified as an inelastic collision with a loss in kinetic energy, expressed in scientific notation, of a.bc x 10 d %. The values of a, b, c, and d, are,,, and. (Record your four digit answer on the numerical response section of your answer booklet.) 15. A 0.22 kg ball moving due south at 27 m/s is struck by a wooden bat, changing its velocity to 36 m/s north. If the bat is in contact with the ball for 0.57 s, what is the magnitude of the impulse on the ball? a. 2.0 N s b. 8.0 N s c. 14 N s d. 24 N s 16. At a track meet, a 70.0 kg student jumps 2.10 m over a high jump pole. When the student hits the ground, he bends his legs to cushion the fall and extends the stopping time to 0.0400 s. What is the average force acting on the student? a. 1.12 10 4 N b. 1.22 10 4 N c. 1.32 10 4 N d. 1.42 10 4 N 17. A truck with a mass of 4.00 x 10 4 kg is travelling at 100.0 km/h. If the driver reduces the truck's speed to 60.0 km/h, then the truck's kinetic energy has changed by a. -2.22 x 10 4 J b. -9.88 x 10 6 J c. -3.20 x 10 7 J d. -1.28 x 10 8 J 18. The gravitational potential energy, kinetic energy, and mechanical energy of a bungee jumper during the free-fall portion of a jump are graphed below. Lines A, B, and C represent, respectively, a. mechanical energy, gravitational potential energy, and kinetic energy b. mechanical energy, kinetic energy, and gravitational potential energy c. gravitational potential energy, mechanical energy, and kinetic energy d. kinetic energy, gravitational potential energy, and mechanical energy
Use the following information to answer the next two questions. During an archery competition, an arrow of mass 35.0 g is fired horizontally with a speed of 1.10 x 10 2 m/s at a target fixed to a wall. The arrow does not drop significantly during its flight. The arrow penetrates the target to a depth of 5.00 cm and is brought to a complete stop. 19. The kinetic energy of the arrow as it leaves the bow is a. 4.24 x 10 5 J b. 2.12 x 10 5 J c. 4.24 x 10 2 J d. 2.12 x 10 2 J 20. The magnitude of the average force exerted by the target on the arrow, expressed in scientific notation, is a.bc x 10 d N. The values of a, b, c, and d, are,,, and. (Record all four digits of your answer as in the numerical-response section on the answer sheet.) 21. A 4.50 kg bag of sugar initially at rest on the edge of a shelf falls. When the bag of sugar is 1.50 m above the floor, it has a total mechanical energy, with respect to the floor, of 95.3 J. The height of the shelf from which the bag fell is m. (Record your three-digit answer in the numerical-response section on the answer sheet.) 22. A frictionless 3.0 kg cart rolls down an incline, and then "loops the loop." From what minimum height, h, should the cart be released so that it does not fall off the circular track? a. 12.0 m b. 15.0 m c. 18.0 m d. 24.0 m 23. In a one-dimensional collision experiment, students recorded these data. What is the manipulative variable? a. Mass b. Velocity c. Momentum d. Kinetic Energy
24. Students do an experiment about the conservation of energy by placing a puck at the top an inclined air table and letting the puck go so that it accelerates down to the bottom of the table. Measurements of mass, distance, and time are recorded and the students calculate the puck's energy at the bottom of the incline. In this experiment, what is the controlled variable? a. Average speed of the puck b. Acceleration due to gravity c. Kinetic energy of the puck d. Time for puck to go down plane kp Y = X 25. A formula that relates the two variables Y and X is. If you decide to graph Y as some function of X to obtain a linear graph. Which of the following will give a linear graph with k as its slope? a. Y as a function of X b. Y -1 as a function of X 2 c. Y as a function of X 2 d. Y as a function of 1 X