You (mass 55 kg) are riding your frictionless skateboard (mass 5.0 kg) in a straight line at a speed of 4.5 m/s when a friend standing on a balcony above you drops a 2.5 kg sack of flour straight down into your arms. (a) What is your new speed, while holding the flour sack? (b) Since the sack was dropped vertically, how can it affect your horizontal motion? Explain. (c) Suppose you now try to rid yourself of the extra weight by throwing the flour sack straight up. What will be your speed while the sack is in the air? Explain.
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
College Physics (10th Edition)
Additional Science Textbook Solutions
College Physics
The Cosmic Perspective
Life in the Universe (4th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Lecture- Tutorials for Introductory Astronomy
Cosmic Perspective Fundamentals
- A cart filled with sand rolls at a speed of 1.0 m/s along a horizontal path without friction. A ball of mass m = 2.0 kg is thrown with a horizontal velocity of 8.0 m/s toward the cart as shown in Figure P11.79. The ball gets stuck in the sand. What is the velocity of the cart after the ball strikes it? The mass of the cart is 15 kg. FIGURE P11.79 Problems 79 and 80.arrow_forwardFrom what might be a possible scene in the comic book The X-Men, the Juggernaut (mJ) is charging into Colossus (mC) and the two collide. The initial speed of the Juggernaut is vJi and the initial speed of Colossus is vCi. After the collision, the final speed of the Juggernaut is vJf and the final speed of Colossus is vCf as they each bounce off of the other, heading in opposite directions. a. What is the impulse experienced by the Juggernaut? b. What is the impulse experienced by Colossus? c. In your own words, explain how these impulses must compare with each other and how they are related to the average force each superhero experiences during the collision.arrow_forwardThere is a compressed spring between two laboratory carts of masses m1 = 105 g and m2 = 212 g. Initially, the carts are held at rest on a horizontal track (Fig. P10.40A). The carts are released, and the cart of mass m1 has velocity vi=2.035i m/s in the positive x direction (Fig. 10.40B). Assume rolling friction is negligible. a. What is the net external force on the two-cart system? b. Find the velocity of cart 2. FIGURE P10.40 Problems 40 and 41.arrow_forward
- An astronaut out on a spacewalk to construct a new section of the International Space Station walks with a constant velocity of 2.00 m/s on a flat sheet of metal placed on a flat, frictionless, horizontal honeycomb surface linking the two parts of the station. The mass of the astronaut is 75.0 kg, and the mass of the sheet of metal is 245 kg. a. What is the velocity of the metal sheet relative to the honeycomb surface? b. What is the speed of the astronaut relative to the honeycomb surface?arrow_forwardA rocket has total mass Mi = 360 kg, including Mfuel = 330 kg of fuel and oxidizer. In interstellar space, it starts from rest at the position x = 0, turns on its engine at time t = 0, and puts out exhaust with relative speed ve = 1 500 m/s at the constant rate k = 2.50 kg/s. The fuel will last for a burn time of Tb = Mfuel/k = 330 kg/(2.5 kg/s) = 132 s. (a) Show that during the burn the velocity of the rocket as a function of time is given by v(t)=veln(1ktMi) (b) Make a graph of the velocity of the rocket as a function of time for times running from 0 to 132 s. (c) Show that the acceleration of the rocket is a(t)=kveMikt (d) Graph the acceleration as a function of time. (c) Show that the position of the rocket is x(t)=ve(Mikt)ln(1ktMi)+vet (f) Graph the position during the burn as a function of time.arrow_forwardProblems 44 and 45 are paired. C A model rocket is shot straight up. As it reaches the highest point in its trajectory, it explodes in midair into three pieces with velocities indicated by the arrows in Figure P10.44, as viewed from directly above the explosion. Rank the mass of each piece in order from smallest to largest and justify your answer. FIGURE P10.44 Problems 44 and 45.arrow_forward
- A mother pushes her son in a stroller at a constant speed of 1.52 m/s. The boy tosses a 56.7-g tennis ball straight up at 1.75 m/s and catches it. The boys father sits on a bench and watches. a. According to the mother, what are the balls initial and final momenta? b. According to the father, what are the balls initial and final momenta? c. According to the mother, is the balls momentum ever zero? If so, when? If not, why not? d. According to the father, is the balls momentum ever zero? If so, when? If not, why not?arrow_forwardA model rocket engine has an average thrust of 5.26 N. It has an initial mass of 25.5 g, which includes fuel mass of 12.7 g. The duration of its burn is 1.90 s. (a) What is the average exhaust speed of the engine? (b) This engine is placed in a rocket body of mass 53.5 g. What is the final velocity of the rocket if it were to be fired from rest in outer space by an astronaut on a spacewalk? Assume the fuel burns at a constant rate.arrow_forwardA ball of mass 250 g is thrown with an initial velocity of 25 m/s at an angle of 30 with the horizontal direction. Ignore air resistance. What is the momentum of the ball after 0.2 s? (Do this problem by finding the components of the momentum first, and then constructing the magnitude and direction of the momentum vector from the components.)arrow_forward
- This is a symbolic version of Problem 23. A girl of mass mG is standing on a plank of mass mp. Both are originally at rest on a frozen lake that constitutes a frictionless, flat surface. The girl begins to walk along the plank at a constant velocity vGP to the right relative to the plank. (The subscript GP denotes the girl relative to plank.) (a) What is the velocity vPI of the plank relative to the surface of the ice? (b) What is the girls velocity vGI relative to the ice surface?arrow_forwardFigure P9.59a shows an overhead view of the configuration of two pucks of mass In on frictionless ice. The pucks are tied together with a string of length 1' and negligible mass. At time t = 0, a constant force of magnitude F begins to pull to the right on the center point of the string. At time t, the moving pucks strike each other and stick together. At this time, the force has moved through a distance 4 and the pucks have attained a speed v (Fig. P9.59b). (a) What is v in terms of F, d, e, and in? (b) How much of the energy transferred into the system by work done by the force has been transformed to internal energy?arrow_forward▼ Part A 0.100 kg stone rests on a frictionless, horizontal surface. A bullet of mass 6.50 g , traveling horizontally at 310 m/s, strikes the stone and rebounds horizontally at right angles to its original direction with a speed of 250 m/s . Compute the magnitude of the velocity of the stone after it is struck. ? m/s %3D Submit Request Answer Part B Compute the direction of the velocity of the stone after it is struck. Σφ ? from the initial direction of the bullet Submit Request Answer IIarrow_forward
- Classical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningUniversity Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University