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Usually, we do not walk or even stand on a lightweight boat or raft because of the danger of falling into the water. If you have ever stepped off a small boat onto a dock, however, you have probably noticed that the boat moves away from the dock as you step toward the dock or out of the boat. A heavy dog running on a long lightweight raft presents a similar situation. At first, the raft and the dog are at rest with respect to the water (Fig. P10.38A) so that
FIGURE P10.38
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Chapter 10 Solutions
Physics for Scientists and Engineers: Foundations and Connections
- 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 Chinook salmon can swim underwater at 3.58 m/s, and it can also jump vertically upward, leaving the water with a speed of 6.26 m/s. A record salmon has length 1.50 m and mass 61.0 kg. Consider the fish swimming straight upward in the water below the surface of a lake. The gravitational force exerted on it is very nearly canceled out by a buoyant force exerted by the water. The fish experiences an upward force P exerted by the water on its threshing tail fin and a downward fluid friction force that we model as acting on its front end. Assume the fluid friction force disappears as soon as the fish’s head breaks the water surface and assume the force on its tail is constant. Model the gravitational force as suddenly switching full on when half the length of the fish is out of the water. Find the value of P.arrow_forwardAs a fish jumps vertically out of the water, assume that only two significant forces act on it: an upward force F exerted by the tail fin and the downward force due to gravity. A record Chinook salmon has a length of 1.50 m and a mass of 54.5 kg. If this fish is moving upward at 3.00 m/s as its head first breaks the surface and has an upward speed of 6.30 m/s after two-thirds of its length has left the surface, assume constant acceleration and determine the following. (a) the salmon's acceleration m/s2 upward (b) the magnitude of the force F during this intervalarrow_forward
- You are pulling your younger sister along in a small wheeled cart. You weigh 65.0 kg and the combined mass of your sister and the cart is 35.0 kg. You are pulling the cart via a short rope which you pull horizontally. You hold one end of the rope and your sister holds the other end. If you are accelerating at a rate of 0.10 m s−2, the rope is inelastic, and the frictional force acting upon the cart is 30 N: a) What is the tension in the rope? (b) What force are you applying to the ground in order to produce this acceleration?arrow_forwardAs a fish jumps vertically out of the water, assume that only two significant forces act on it: an upward force F exerted by a tail fin and the downward force due to gravity. A record Chinook salmon has a length of 1.50 m and a mass of 48.5 kg. if this fish is moving upward at 3.00 m/s as its head first breaks the surface and has an upward speed of 5.80 m/s after two-thirds of its length has left the surface. what is the magnitude of the force F during the intervalarrow_forwardA fisherman has caught a very large, 5.0 kg fish from a dock that is 2.0 m above the water. He is using lightweight fishing line that will break under a tension of 54 N or more. He is eager to get the fish to the dock in the shortest possible time. If the fish is at rest at the water’s surface, what’s the least amount of time in which the fisherman can raise the fish to the dock without losing it?arrow_forward
- You are locked inside the train car and want to get it moving to draw attention to your plight. There is effectively no friction between the axle and the car, and the train is on horizontal tracks. To try and get the car moving with respect to the ground, you run and slam with all your force against the wall at the front. What happens with the car after you slammed against the wall of the car? (A) The car starts moving forward at constant speed and keeps moving. (B) The car starts moving backward at constant speed and keeps moving. (C) The car moves briefly as you run, but stops again after you run into the wall (D) You only hurt your shoulder; the car doesn't move at all at any time.arrow_forwardThe engines of a tanker broke down and the wind pushes the ship with a constant speed of 1.5 m / s straight towards a reef. When the boat is 500 m from the reef, the wind stops and the engineer manages to start the engines. The rudder is stuck, so the only option is to try to accelerate backwards. The mass of the ship and its cargo is 3.6 x 107 kg and the engines produce a net horizontal force of 8 x 104 N. The hull can withstand impacts at a speed of 0.2 m / s or less. The retarding force that the water exerts on the hull of the ship can be neglected. a) The equation of motion that corresponds to the horizontal component is? b)The acceleration of the ship is equal to? c) If the reef does not exist, the vessel, before stopping, travels what distance?arrow_forwardA hockey puck (mass = 4 kg) leaves the players stick with a speed of 12 m/s and slides on the ice before coming to rest. The coefficient of friction between the puck and the ice is 0.3. How far will the puck slide after leaving the players stick?arrow_forward
- A hammer of mass m = 0.45 kg is moving horizontally at a velocity of v = 5.5 m/s when it strikes a nail and comes to rest after driving the nail a distance Δx = 1.05 cm into a board. Part (a) What is the duration of the impact, assuming the acceleration is constant during this time period, in terms of the given variables? Part (b) What was the average force exerted on the nail, in terms of the mass, initial velocity, and distance traveled? Part (c) What was the average force, in newtons, exerted on the nail?arrow_forwardA hockey puck with mass 0.160 kg is at rest at the origin 1x = 02 on the horizontal, frictionless surface of the rink. At time t = 0 a player applies a force of 0.250 N to the puck, parallel to the x-axis; she continues to apply this force until t = 2.00 s. (a) What are the position and speed of the puck at t = 2.00 s? (b) If the same force is again applied at t = 5.00 s, what are the position and speed of the puck at t = 7.00 s?arrow_forwardScientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 7.6-kg projectile from rest to a speed of 5.1 × 103 m/s. The net force accelerating the projectile is 6.4 × 105 N. How much time is required for the projectile to come up to speed?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningClassical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage Learning