PHY 101 Exam 1 Fall 2019 Student Name: PRINT Last Name:_________________First Name_______________ ID# __________________ Signature_________________ Recitation Section #/TA Name: ______________________ (Jeremy, Courtney, Gabriel, Michael, Jianyang, Wei Chen) • You are allowed a calculator and ONE 8.5”x11” sheet of paper with whatever you wish written on it (both sides). • You must show ALL your work to receive full credit for regular problems. Numerical answers must have the right units. • Use the back of the problem page if you need more space and mark OVER on the front to indicate that there is material on the back side. • For the multiple-choice questions, clearly write the letter of your choice on the front page. No points will be given if two or more choices are circled Answers to Multiple Choice Questions: (Please write the answers clearly here) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Please note that giving or receiving aid on an exam or any act of academic dishonesty is cause for dismissal from the University. Question Score Grader 1 - 12 13 _____ _______ 14 _____ _______ 15 16 TOTAL _____ _______ USEFUL CONSTANTS: Acceleration due to gravity: g = 9.8 m/s2Multiple Choice Questions You do not need to show your work. Please write down the answer on the front page. No partial credit will be given. (3 points each) 1) A bottle has a volume of 5.4 L. What is its volume in cubic meters? (Remember: 1 L is a cube with 10 cm side length.) (A) 0.054 m3 (B) 0.0054 m3 (C) 0.54 m3 (D) 5.4 m3 /2 2) Suppose A = BC, where A has the dimensions L/M and C has the dimensions L/T. Then B has the dimension: (A) T/M (B) TM (C) M/T (D) M + T 3) A person on horseback moves according to the velocity-versus-time graph shown in the figure. Rank the displacements of the person during each segment from the smallest to the largest. (A) A, B, C (C) B, A, C (C) C, A, B (D) C, B, A 4) The figure below shows strobe photographs taken of a disk moving from left to right under different conditions. The time interval between images is constant. Taking the direction to the right to be positive, which description of the motion is correct? (A) the acceleration is negative (B) the acceleration is positive (C) is the velocity constant (D) the disk is at rest 5) A ladder 6.90 m long leans against a vertical wall. If the ladder is inclined at an angle of 79.0° to the horizontal, what is the horizontal distance from the bottom of the ladder to the wall? (A) 1.32 m (B) 3.06 m (C) 6.77 m (D) 5.49 m 6) Which vector in the figure on the right equals A󰇍󰇍 + B󰇍󰇍 ? (a) (b) (c) (d)7) For a cannon on Earth, the cannonball would follow path b. If the same cannon were instead on the Moon, where g = 1.6 m/s2, which path would the cannonball take in the same situation? time? 8) Debra and Mary stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30° below the horizontal; Debra throws her snowball upward, at 30° above the horizontal. Which of the following statements are true about just before the snowballs reach the ground below? (A) Debra's snowball will have a higher speed than Mary's snowball. (B) Mary's snowball will have a higher speed than Debra's snowball. (C) Both snowballs will hit the ground with the same speed. (D) Both snowballs hit the ground at the same time. 9) Two blocks are connected by a string and pulley as shown. Assuming that the string and pulley are massless, the magnitude of the acceleration of each block is: (A) 0.049 m/s2 (B) 0.98 m/s2 (C) 0.0098 m/s2 (D) 0.54 m/s2 10) If an object of mass m moves with constant velocity v, the net force on the object is which of the following? (A) 𝑚𝑔 (B) 𝑚𝑣 (C) 𝑚𝑣/𝑡 (D) 0 11) In the figure, what does the spring scale read? The pulleys are ideal and the strings and scale are also massless (A) 2 N (B) 1 N (C) 0.5 N (D) 0 N12) A piano mover raises a 1000-N piano at a constant speed using a very light rope in a frictionless pulley system, as shown in the figure. With what force is the mover pulling down on the rope? (A) 2000 N (B) 1000 N (C) 500 N (D) 250 NProblems: You MUST show ALL your work and use correct units for numerical answers to receive full credit. 13) Initially a car is traveling at 56 mph. Then the driver of the car, applies the breaks and the car decelerates uniformly at a rate of 1.2m/s2. (1 mile = 1.61 km ) (a) How far does the car travel in the first 3.0 s after the breaks are applied? (5 points) (b) How long does it take for the car to come to a complete stop? (4 points) (c) What distance does the car travel before coming to a complete stop? (4 points) (d) Now if the car was travelling initially at twice the speed and the same deceleration applied via the breaks, by what factor would the stopping distance change with the answer you got in part (c)? (3 points) (i) it would be the same (ii) by a factor of two (iii) by a factor of four (iv) by a factor of eight (v) by a factor of sixteen14) Your directions to buried treasure read: starting at Wilson’s Grave (the origin) walk 6.0 paces North, then 8.0 paces at an angle 30° South of East, and finally 7.0 paces Southwest (45° South of West). (a) Calculate the x- (East) and y- (North) components (in paces) for each of the three displacment vectors. (6 points) (b) Draw the displacement vectors on the graph, beginning at the origin, to illustrate the path to the treature. (3 points) (c) What are the x- and y- coordinates of the treasure? (4 points) (d) How far (in paces) and in what direction is the treasure from Wilson’s grave? (3 points)15) A stone is thrown off the top of a building from a height of 40.0 m. The stone has a launch angle of 63.5°