Concept explainers
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
- You are holding a basketball and standing at rest on top of a skateboard. If you throw the basketball (of mass 0.625 kg) at a velocity of 7 m/s along the horizontal and you and the skateboard together have a mass of 85 kg, what is the magnitude of your velocity just after throwing the ball? Assume you can ignore air resistance, rolling resistance, and friction.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_forwardAn 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_forward
- To lift off from the Moon, a 9.50 105 kg rocket needs a thrust larger than the force of gravity. If the exhaust velocity is 4.25 103 m/s, at what rate does the exhaust need to be expelled to provide sufficient thrust? The acceleration due to gravity on the Moon is 1.62 m/s2.arrow_forwardA 6100 kg rocket is set for vertical firing from the ground. If the exhaust speed is 1200 m/s, how much gas must be ejected each second if the thrust (a) is to equal the magnitude of the gravitational force on the rocket and (b) is to give the rocket an initial upward acceleration of 21 m/s2?arrow_forwardDuring the filming of a certain movie scene, the director wants a small car (whose mass is m1) traveling due east at speed v1 to collide with a small truck (whose mass is m2) traveling north. The director also wants the collision to be arranged so that just afterward, the interlocked vehicles travel straight toward the camera. If the line between the camera and collision makes an angle of theta with respect to north, at what speed v2 should the trucker drive?arrow_forward
- A 1500 g model rocket is resting horizontally at the top edge of a 40m-high wall when it is accidentally bumped. The bump pushes it off the edge with a horizontal speed of 0.5 m/s and at the same time causes the engine to ignite. When the engine fires, it exerts a constant 20 N horizontal thrust away from the wall. How far from the base of the wall does the rocket land?arrow_forwardIn this problem, we assume that the motion is taking place on a frictionless surface.Let us consider two balls A and B having the same masse. Initially, the ball B is at rest and the ball A is moving with the speed ?? = 3.00 ?/? in the +? direction as seen in the figure.After the ball A hits (or collides with) the ball B, they are both observed to move off at 45° to the x axis,ball A above the x axis and ball B below. So ?′A= 45° and ?′B = −45°.1- What are the speeds of the two balls ?⃗′A and ?⃗′B after the collision?arrow_forwardYou hold glider AA of mass 0.125 kgkg and glider BB of mass 0.375 kgkg at rest on an air track with a compressed spring of negligible mass between them. When you release the gliders, the spring pushes them apart. Once the gliders are no longer in contact with the spring, glider AA is moving to the right at 0.600 m/sm/s. What is the velocity (magnitude and direction) of glider BB at this time? Express your answer with the appropriate units. Enter positive value if glider BB is moving to the right and negative value if glider BB is moving to the left. b) Glider AA moving to the right at 0.600 m/sm/s then collides head-on with a third glider CC of mass 0.750 kgkg that is moving to the left at 0.400 m/sm/s. After this collision, glider CC is moving to the left at 0.150 m/sm/s. What is the velocity (magnitude and direction) of glider AA after this collision? Express your answer with the appropriate units. Enter positive value if glider AA is moving to the right and negative value if…arrow_forward
- At time t=0, constant F begins to act on a rock moving through deep space in the +x direction. For time t>0, which are possible function x(t) for the rock's position : (1)x=4t-3 (2) x=-4t^2+6t-3 (3) x=4t^2+6t-3?arrow_forwardIf two objects A and B have the same kinetic energy but A has four times the momentum of B, what is the ratio of their inertias?arrow_forwardHuman reaction time is usually about 0.20 s. If your lab partner holds a ruler between your finger and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it? The nearest value is: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