University Physics Volume 1
18th Edition
ISBN: 9781938168277
Author: William Moebs, Samuel J. Ling, Jeff Sanny
Publisher: OpenStax - Rice University
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Textbook Question
Chapter 9, Problem 11CQ
A sprinter accelerates out of the starting blocks. Can you consider him as a closed system? Explain.
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Check out a sample textbook solutionStudents have asked these similar questions
A man climbs a mountain. The man is of mass m falling freely in length h until the elastic rope starts
to slow the fall at y = 0 and t=to= 0. At this time the climber has speed vo. The rope has length Lis
fixed at point S and is without slack in the place where the climber fell.
-The climber is in free fall until the rope starts to catch the fall. Set up the model that applies to free
fall and derive the expression for the speed vo the climber has in the rope that starts to slow the fall.
you can assume that the speed of the climber is just a function of y such that:
dy
dt
=v(y) →
L
d²y
==v
dt²
S
dv
dy
2/2
2/2
y = 0
dy
dt
= v(y) ⇒
d²y
dt²
= V
dv
dy
Figure 1: Climbing with mass m falling freely in length h until the elastic rope starts to slow
down the fall at y = 0 and t = to = 0. At this time, the climber has speedvo. The rope has
length L, is fixed at point S, and is without slack as the climber falls.
Calculate for the % difference between the initial and final kinetic energies of the total/whole system for the following:
i) Set-up 1: Trial 1, Trial 2 and Trial 3
Calculate for the % difference between the initial and final kinetic energies of the total/whole system for the following:
ii) Set-up 2: Trial 1, Trial 2 and Trial 3
Chapter 9 Solutions
University Physics Volume 1
Ch. 9 - Check Your Understanding The U.S. Air Force uses...Ch. 9 - Check Your Understanding What if we had assumed...Ch. 9 - Check Your Understanding Suppose the second,...Ch. 9 - Check Your Understanding Would the ball’s change...Ch. 9 - Check Your Understanding Even if there were some...Ch. 9 - Check Your Understanding The changes of momentum...Ch. 9 - Check Your Understanding There is a second...Ch. 9 - Check Your Understanding Suppose there had been no...Ch. 9 - Check Your Understanding Suppose the initial...Ch. 9 - Check Your Understanding Notice that the mass of...
Ch. 9 - Check Your Understanding Suppose we included the...Ch. 9 - Check Your Understanding Suppose you have a...Ch. 9 - Check Your Understanding How would the firework...Ch. 9 - Check Your Understanding What is the physical...Ch. 9 - An object that has a small mass and an object that...Ch. 9 - An object that has a small mass and an object that...Ch. 9 - Is it possible for a small force to produce a...Ch. 9 - Why is a 10-m fall onto concrete far more...Ch. 9 - What external force is responsible for changing...Ch. 9 - A piece of putty and a tennis ball with the same...Ch. 9 - Under what circumstances is momentum conserved?Ch. 9 - Can momentum be conserved for a system if there...Ch. 9 - Explain in terms of momentum and Newton’s laws how...Ch. 9 - Can objects in a system have momentum while the...Ch. 9 - A sprinter accelerates out of the starting blocks....Ch. 9 - A rocket in deep space (zero gravity) accelerates...Ch. 9 - Two objects of equal mass are moving with equal...Ch. 9 - Describe a system for which momentum is conserved...Ch. 9 - Momentum for a system can be conserved in one...Ch. 9 - Suppose a fireworks shell explodes, breaking into...Ch. 9 - It is possible for the velocity of a rocket to be...Ch. 9 - An elephant and a hunter are having a...Ch. 9 - A skater of mass 40 kg is carrying a box of mass 5...Ch. 9 - A car of mass 2000 kg is moving with a constant...Ch. 9 - The mass of Earth is 5.971024kg and its orbital...Ch. 9 - If a rainstorm drops 1 cm of rain over an area of...Ch. 9 - What is the average momentum of an avalanche that...Ch. 9 - What is the average momentum of a 70.0-kg sprinter...Ch. 9 - A 75.0-kg person is riding in a car moving at 20.0...Ch. 9 - One hazard of space travel is debris left by...Ch. 9 - A cruise ship with a mass of 1.00107kg strikes a...Ch. 9 - Calculate the final speed of a 110-kg rugby player...Ch. 9 - Water from a fire hose is directed horizontally...Ch. 9 - A 0.450-kg hammer is moving horizontally at 7.00...Ch. 9 - Prob. 31PCh. 9 - The x-component of a force on a 46-g golf ball by...Ch. 9 - A hockey puck of mass 150 g is sliding due east on...Ch. 9 - A ball of mass 250 g is thrown with an initial...Ch. 9 - Prob. 35PCh. 9 - Two identical pucks collide elastically on an air...Ch. 9 - The figure below shows a bullet of mass 200 g...Ch. 9 - A 20-kg child is coasting at 3.3 m/s over flat...Ch. 9 - A 4.5 kg puffer fish expands to 40 of its mass by...Ch. 9 - Explain why a cannon recoils when it fires a...Ch. 9 - Two figure skaters are coasting in the same...Ch. 9 - A 2000-kg railway freight car coasts at 4.4 m/s...Ch. 9 - A 5.50-kg bowling ball moving at 9.00 m/s collides...Ch. 9 - Ernest Rutherford (the first New Zealander to be...Ch. 9 - A 90.0-kg ice hockey player hits a 0.150-kg puck,...Ch. 9 - A 100-g firecracker is launched vertically into...Ch. 9 - In an elastic collision, a 400-kg bumper car...Ch. 9 - Repeat the preceding problem if the mass of the...Ch. 9 - An alpha particle (4He) undergoes an elastic...Ch. 9 - You are standing on a very slippery icy surface...Ch. 9 - A 35-kg child rides a relatively massless sled...Ch. 9 - A boy sleds down a hill and onto a frictionless...Ch. 9 - Prob. 53PCh. 9 - A billiard ball, labeled 1, moving horizontally...Ch. 9 - A projectile of mass 2.0 kg is fired in the air at...Ch. 9 - Two asteroids collide and stick together. The...Ch. 9 - Prob. 57PCh. 9 - A proton traveling at 3.0106m/s scatters...Ch. 9 - Prob. 59PCh. 9 - A family is skating. The father (75 kg) skates at...Ch. 9 - Prob. 61PCh. 9 - Two cars of the same mass approach an extremely...Ch. 9 - Three point masses are placed at the corners of a...Ch. 9 - Two particles of masses m1 and m2 separated by a...Ch. 9 - Two particles of masses m1 and m2 separated by a...Ch. 9 - Two particles of masses m1 and m2 , move uniformly...Ch. 9 - Two particles of masses m1 and m2 move uniformly...Ch. 9 - Find the center of mass of a one-meter long rod,...Ch. 9 - Find the center of mass of a rod of length L whose...Ch. 9 - Find the center of mass of a rectangular block of...Ch. 9 - Find the center of mass of a rectangular material...Ch. 9 - A cube of side a is cut out of another cube of...Ch. 9 - Find the center of mass of a cone of uniform...Ch. 9 - Find the center of mass of a thin wire of mass in...Ch. 9 - Find the center of mass of a uniform thin...Ch. 9 - Find the center of mass of a sphere of mass M and...Ch. 9 - (a) A 5.00-kg squid initially at rest ejects 0.250...Ch. 9 - A rocket takes off from Earth and reaches a speed...Ch. 9 - Repeat the preceding problem but for a rocket that...Ch. 9 - How much fuel would be needed for a 1000-kg rocket...Ch. 9 - What exhaust speed is required to accelerate a...Ch. 9 - Unreasonable Results Squids have been reported to...Ch. 9 - Two 70-kg canoers paddle in a single, 50-kg canoe....Ch. 9 - Which has a larger magnitude of momentum: a...Ch. 9 - A driver applies the brakes and reduces the speed...Ch. 9 - You friend claims that momentum is mass multiplied...Ch. 9 - Dropping a glass on a cement floor is more likely...Ch. 9 - Your 1500-kg sports car accelerates from 0 to 30...Ch. 9 - A ball of mass m is dropped. 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