12:24 PM Sat Sep 30 e L 83% - r education.wiley.com 6 Chapter 2: Homework 2 Question 2 of8 - / 10 E: .0. As a SOO-kg Moon lander is descending toward the surface, its thruster res an upward force. At a height of 50 m, the lander's velocity is 9.5 m/s downward. At a height of 5 m, its velocity is 0.5 m/s downward. The Moon's gravitational eld strength near its surface is 1.6 N/kg. Assume the mass of the lander remains nearly constant during the process. Part 1 What is the average y-velocity of the lander during this displacement? uanJ : n m/s Save for Later Attempts: 0 of4 used Part 2 What is the time interval during which this displacement occurs? A12\" 5 Save for Later Attempts: 0 of4 used Part 3 What is the y-component of the average net force on the lander during this time interval? Fricty : n N eTextbook and Media Assistance Used 12:24 PM Sat Sep 30 e L 83% -r education.wiley.com 6 Chapter 2: Homework 2 Question 3 of8 5/ 10 E: .0. Current Attempt in Progress An idealized px(t) graph for a programmable fan ca rt on a low-friction surface is shown below. (What makes this graph an idealization are the nearly instantaneous changes in the slope) The fan on the cart can be pre- programmed for the fan to turn on or off, change speed, or change direction at given time intervals. This allows one to control the force on the fan cart programmatically. The mass of the fan cart is 0.7 kg. mm for a programmable fan cart 2.0 1.5 1.0 0.5 E E c 0.0 as :i 0.5 l.0 l.5 2.0 0 2 4 6 8 10 HS) Part 1 V Your answer is correct. What is the rst instant of time when the cart is at a turning point and changes direction? 12:24 PM Sat Sep 30 83% M Chapter 2: H Homework Hell X ckumarad's pre X Free Astronom WP Question 3 of 8 X + education.wiley.com 7 . . . 5 / 10 Save for Later Attempts: 0 of 4 used Submit Answer Part 7 During which of the time intervals is the net force on the cart greatest in magnitude? O Between t = 0 andt = 1 s O Betweent = 1 andt = 4 s O Between t = 4 andt = 9 s O Between t = 9 andt = 9.5 s O Betweent = 9.5 andt = 10.0 s Save for Later Attempts: 0 of 4 used Submit Answer Part 8 At what time between t = 0 and t = 8 s does the net force on the cart change from the + x direction to the - x direction? eTextbook and Media Save for Later Attempts: 0 of 4 used Submit Answer12:24 PM Sat Sep 30 :- L 83% - m Chapter 2:r Homeworkl O ckumarad's E Free Astronc Question4of X -l- 6 Cl educationwileycom Q; ['1'] ... 6 Chapter 2: Homework 2 Question 4 of8 - / 15 E at. _> Two different experiments are performed. In the first experiment, a constant force F is applied to a hydrogen _) ion. In the second experiment, the same constant applied force F is applied to an ion that has a mass 16 times the mass of hydrogen. In each experiment, the ion is at rest at location A. Note that this force is much larger than any possible gravitational force on the ions, so you can neglect gravity. A 8' A 8" 17' 17' B B Part 1 t. 1011 7 Am ' What is the ratio of the time interval for each ion to travel from A to B, Alion _ n AIH Save ior Later Attempts: 0 of4 used Part 2 \"3.1011 What is the ratio of the speeds of the ions as they pass location B, ? UBTion _ n UB.H UBJi 12:24 PM Sat Sep 30 83% M Chapter 2: H Homework Hell X ckumarad's pre X Free Astronom WP Question 4 of 8 X + education.wiley.com 7 . . . 1.67/15 E: on. Save for Later Attempts: 0 of4 used Part 5 Now, at t = 0.1 5, what is the net force by the springs on the cart? > an(r=0.1s)=m eTextbook and Media Save for Later Attempts: 0 of4 used 12:25 PM Sat Sep 30 83% M Chapter 2: H Homework Hell X ckumarad's pre X Free Astronom WP Question 6 of 8 X + education.wiley.com 7 . . . - Chapter 2: Homework 2 Question 6 of 8 - / 10 E Current Attempt in Progress A tennis ball has a mass of 0.057 kg. A professional tennis player hits the ball hard enough to give it a speed of 47 m/s (about 105 miles per hour.) The ball moves toward the left, hits a wall and bounces straight back to the right with almost the same speed (47 m/s). As indicated in the diagram below, high-speed photography shows that the ball is crushed about d = 2.0 cm at the instant when its speed is momentarily zero, before rebounding. Making the very rough approximation that the large force that the wall exerts on the ball is approximately constant during contact, determine the approximate magnitude of this force. Part 1 (a) What is the average speed of the ball during the period from first contact with the wall to the moment the ball's speed is momentarily zero? W avg | = i m/s Save for Later Attempts: 0 of 4 used Submit Answer Part 2 (b) How much time elapses between first contact with the wall, and coming to a stop? At = i S Save for Later Attempts: 0 of 4 used Submit Ans12:25 PM Sat Sep 30 ... ... L 83%l:]' education.wiley.com 6 Chapter 2: Homework 2 Question 6 of8 - / 10 E: on. Part 2 (b) How much time elapses between rst contact with the wall, and coming to a stop? Ar : n 5 Save for Later Attempts: 0 of4 used Part 3 (c) What is the magnitude of the average force exerted by the wall on the ball during contact? _> IF avg : n N Save for Later Attempts: 0 of4 used Part 4 (cl) In contrast, what is the magnitude of the gravitational force of the Earth on the ball? mg : n N eTextbook and Media Save for Later Attempts: 0 of4 used 12:25 PM Sat Sep 30 83% M Chapter 2: H Homework Hell X ckumarad's pre X Free Astronom WP Question 7 of 8 X + education.wiley.com 7 . . . m Save for Later Attempts: 0 of4 used Part 2 w= kg-m/s eTextbook and Media Save for Later Attempts: 0 of4 used 12:26 PM Sat Sep 30 . . . 83% I ckumar = Free Astronomy X New Tab X WP NWP Assessme X WP Question 2 of 1 X F education.wiley.com 7 . . . - Chapter 2: Homework 1 Question 2 of 10 -15 3 Current Attempt in Progress Your lab partner jumps off a lab table and lands on the floor. Using video analysis, you measure her y-velocity during a certain time interval during the collision with the floor and graph py (t) as shown below. Her mass is 55 kg. The slope of the best-fit line is 2625 kg.m/$2. Py(t) during a landing best-fit line -60 -80 -100 -120 Py (kg m/s) -140 -160 -180 -200 1.04 1.05 1.06 1.07 1.08 1.09 1.10 t (s) Part 1 During this time interval, what is the y-component of the average net force on her? Fnet,y i N Save for Later12:26 PM Sat Sep 30 . . . 83% education.wiley.com Question 2 of 10 -15E Fnet,y i N Save for Later Attempts: 0 of 4 used Submit Answer Part 2 What is the y-component of the force by the floor on her during the collision? Ffloor,y = i N Save for Later Attempts: 0 of 4 used Submit Answer Part 3 How does the force by the floor on her during the collision compare to the force by Earth? Calculate the F floor ratio, F grav F floor F grav eTextbook and Media Save for Later Attempts: 0 of 4 used Submit Answer12:26 PM Sat Sep 30 :- L 83% - O ckumare E Free Astronc New Tab NWP Assess Question 5 of X -l- 6 Cl educationwileycom Q; ['1'] ... 6 Chapter 2: Homework 1 Question 5 oin 3.33/10 ;: at. View Policies Show Attempt History Current Attempt in Progress I Your answer is partially correct. A 0.045-kg golf ball is rolling toward the hole with an approximately constant velocity (0.5, 0, 0) m/s. At t = 0.90 s it hits the edge of the hole. It then travels around the hole and continues rolling at a nearly constant momentum. It leaves the hole at t = 1.2 s with a speed 0.39 m/s in the direction (0.45, 0.90, 0).A picture of the ball before and after the interaction is shown below. What is the average net force on the golf ball during the time interval that the ball interacts with the hole? _) awn II HEW eTextbook and Media Assistance Used Hint Save for Later Last saved 1 hour ago. Attempts: 1 of 4 used 12:26 PM Sat Sep 30 - I - . L 83% E} educationwileycom Question 6 of10 3.33/10 E on. Air hockey is a game played on a table. A puck (shown in black) slides freely on a cushion of air. Opposing players strike the puck with a hand-held round \"paddle" (shown in red). In one case, while playing air hockey, the puck comes toward you with a speed of 0.8 m/s at an angle of 30 above the -x axis in the x2 plane. You strike it with your paddle, and after the collision, the puck travels in the +x direction with a speed of 2.0 m/s toward the opponent's goal. The mass of the puck is 0.020 kg. | _\\' paddle . . 3 puck Part 1 V Your answer is correct. +3: paddle. +2 puck In the area below. move the E,- arrow as needed1 then move the ,6} arrow so that it represents the momentum of the puck after the collison. Then, move the A}? vector so that it represents the net impulse on the puck during the collision with the paddle. 12:27 PM Sat Sep 30 . . . 83% education.wiley.com Question 6 of 10 3.33 / 10 Calculate the net impulse on the puck during the collision with the paddle. Fnet At = i 0.0256506 0 0.0125 ) N 'S Hint Assistance Used Save for Later Attempts: 2 of 4 used Submit Answer Part 3 What is the unit vector in the direction of the net impulse? F net = ( i i i Save for Later Attempts: 0 of 4 used Submit Answer Part 4 The contact between the puck and paddle lasted for 5 ms. During this time, what was the average force by the paddle on the puck? F paddle = ( i IN eTextbook and Media Save for Later Attempts: 0 of 4 used Submit Ans12:27 PM Sat Sep 30 :- L 83% - 0 ckumare E Free Astrom New Tab NWP Assess Question 7 of X -l- 6 Cl education.wiley.c0m Q; ['1'] ... 6 Chapter 2: Homework 1 Question 7 0f10 2.22 / 10 E at. Current Attempt in Progress At a certain instant, the velocity of a ODS-kg model rocket is (0, 2.9, 0) m/s, and all signicant forces on the rocket are: > Fthrust by exhaust on rocket : N _) Fgrav by Earth on rocket = (O: _ 0-497 0) N > Flay air on rocket : (0' _ 1'290> N What is the net force on the rocket? ) FINED Hint Assistance Used See Section 2.1. The "net" force acting on a system at an instant is the vector sum of all the forces exerted on the system by all the objects in the surroundings at that instant. Save ior Later Attempts: 1 of4 used Part 2 12:27 PM Sat Sep 30 . . . 83% education.wiley.com Question 7 of 10 2.22 / 10 Save for Later Attempts: 1 of 4 used Submit Answer Part 2 Assuming the mass of the rocket is approximately constant, what will be the rocket's momentum 0.02 s later? P = i i i kg.m/s Save for Later Attempts: 0 of 4 used Submit Answer Part 3 What will be the rocket's displacement over this 0.02 s interval? AT = ( i i ) m eTextbook and Media Assistance Used Save for Later Attempts: 0 of 4 used Submit Answer12:27 PM Sat Sep 30 . . . 83% In ckumar = Free Astronomy X New Tab X WP NWP Assessme X WP Question 8 of 1 X C education.wiley.com 7 . . . - / 10 E: on. View Policies Current Attempt in Progress Suppose you are navigating a spacecraft far from other objects. The mass of the spacecraft is 2.7 X 104 kg (about 27 tons). The rocket engines are shut off, and you're coasting along with a constant velocity of km/s. As you pass the location krn you briey re side thruster rockets, so that your spacecraft experiences a net force of N for 19.0 s. The ejected gases have a mass that is small compared to the mass of the spacecraft. You then continue coasting with the rocket engines turned off. Where are you an hour later? (Think about what approximations or simplifying assumptions you made in your analysis. Also think about the choice of system: what are the surroundings that exert external forces on your system?) _). eTextbook and Media Save for Later Attempts: 0 of 4 used 12:27 PM Sat Sep 30 ?L83%- 0 ckumare E FreeAstronc New Tab NWP Assess Question100 X -l- 6 Cl educationwileycom Q; ['1'] ... 6 Chapter 2: Homework 1 Question 10 of 10 m with velocity m/s. At this low velocity air resistance is negligible. Using the iterative method shown in Section 2.4 with a time step of 0.05 s, calculate step by step the position and velocity of the block at t = 0.05 5,! = 0.10 s, and t = 0.15 5. (Express your answers in vector form.) Part 1 (a)7'(t = 0.055) = m/s Save for Later Attempts: 0 of4 used Part 3 12:28 PM Sat Sep 30 . . . 83% education.wiley.com Question 10 of 10 m Save for Later Attempts: 0 of 4 used Submit Answer Part 4 (d) 7 (1 = 0.10s) = m/s Save for Later Attempts: 0 of 4 used Submit Answer Part 5 (e) T (t = 0.15 s) = m Save for Later Attempts: 0 of 4 used Submit Answer Part 6 (f) 7 (1 = 0.15s) = m/s eTextbook and Media<>