College Physics (10th Edition)
10th Edition
ISBN: 9780321902788
Author: Hugh D. Young, Philip W. Adams, Raymond Joseph Chastain
Publisher: PEARSON
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Question
Chapter 8, Problem 45P
(a)
To determine
The location of the centre of mass of the leg relative to the hip joint if it is fully extended.
(b)
To determine
The location of the centre of mass of the leg relative to the hip joint if it is bent.
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To keep the calculations fairly simple, but still reasonable, we shall model a human leg that is 92.0 cm long (measured from the hip joint) by assuming that the upper leg and the lower leg (which includes the foot) have equal lengths and that each of them is uniform. For a 70.0 kg person, the mass of the upper leg is 8.60 kg, while that of the lower leg (including the foot) is 5.25 kg. Find the location of the center of mass of this leg, relative to the hip joint, if it is (a) fully extended, and (b) bent at the knee to form a right angle with the upper leg.
uman Body
e is 0
1.
In the figure below, the masses of each object are: m₁ = 1 kg, m₂ = 4 kg, m3 = 5 kg.
The labeled distances are: d₁ = 26 cm, d₂ = 100 cm, d3 = 60 cm (where d is the x distance for the
center of the block).
The height of each block is h₁ = 19, h₂ = 30 cm, and the h3 = 10 cm.
Assume the center of mass for each individual object is at the center of the object.
Hint: Consider the final center of mass (x,y) relative to the axes shown in the figure. Note the
positions of the boxes relative to the axes and to one another.
Determine the positions, x and y, of the center of mass for the system below.
Center of mass (x, y):
dl
m1
d3
d2
h1
m3
cm
m2 h2
7h3
X
cm)
A rod of length 3 meters with density 8(x) = 1.1 + 1.1x4grams/meter is positioned along the positive x-axis, with its left end at the
origin. Find the total mass and the center of mass of the rod.
Round your answers to four decimal places.
The total mass of the rod is i
The center of mass of the rod is i
grams.
meters.
Chapter 8 Solutions
College Physics (10th Edition)
Ch. 8 - The objects shown in Figure 8.31 move together....Ch. 8 - Gliders A and B are headed directly toward each...Ch. 8 - Example 8.3 and some of the problems in this...Ch. 8 - Is the momentum of a satellite in a circular orbit...Ch. 8 - Prob. 5CQCh. 8 - A woman stands in the middle of a perfectly...Ch. 8 - (a) If the momentum of a single object is equal to...Ch. 8 - (a) When a large car collides with a small car,...Ch. 8 - When rain falls from the sky, what becomes of the...Ch. 8 - In a zero-gravity environment, can a...
Ch. 8 - A machine gun is fired at a steel plate. Is the...Ch. 8 - At the highest point in its parabolic trajectory,...Ch. 8 - A small car collides head-on with a large SUV....Ch. 8 - In which of the following collisions would you...Ch. 8 - A rifle of mass M is initially at rest, but is...Ch. 8 - Two carts, one twice as heavy as the other, are at...Ch. 8 - Two masses, M and 5M, are at rest on a horizontal...Ch. 8 - A glider airplane is coasting horizontally when a...Ch. 8 - Which of the following statements is true for an...Ch. 8 - Which of the following statements is true for an...Ch. 8 - Cart A, of mass 1 kg, is initially moving to the...Ch. 8 - Two lumps of day having equal masses and speeds,...Ch. 8 - A heavy rifle initially at rest fires a light...Ch. 8 - You drop an egg from rest with no air resistance....Ch. 8 - For each case in Figure 8.33, the system consists...Ch. 8 - For each case in Figure 8.34, the system consists...Ch. 8 - Three objects A, B, and C are moving as shown in...Ch. 8 - A 2646 lb car is moving on the freeway at 68 mph....Ch. 8 - The speed of the fastest-pitched baseball was 45...Ch. 8 - Cart A has a mass of 5 kg and is moving in the +x...Ch. 8 - The magnitude of the momentum of a cat is . What...Ch. 8 - Two figure skaters, one weighing 625 N and the...Ch. 8 - Recoil speed of the earth. In principle, any time...Ch. 8 - On a frictionless air track, a 0.150 kg glider...Ch. 8 - You are standing on a sheet of ice that covers the...Ch. 8 - On a frictionless, horizontal air table, puck A...Ch. 8 - Block A in Figure 8.36 has mass 1.00 kg, and block...Ch. 8 - A 750 kg car is stalled on an icy road during a...Ch. 8 - You (mass 55 kg) are riding your frictionless...Ch. 8 - A 4.25 g bullet traveling horizontally with a...Ch. 8 - A ball with a mass of 0.600 kg is initially at...Ch. 8 - Combining conservation laws. A 5.00 kg chunk of...Ch. 8 - Combining conservation laws. 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The mass of a regulation tennis ball...Ch. 8 - To warm up for a match, a tennis player hits the...Ch. 8 - A 150 g baseball is hit toward the left by a bat....Ch. 8 - Your little sister (mass 25.0 kg) is sitting in...Ch. 8 - A 270 caliber hunting rifle fires an 8.5 g bullet,...Ch. 8 - Calculate the location of the center of mass of...Ch. 8 - Prob. 42PCh. 8 - Three odd-shaped blocks of chocolate have the...Ch. 8 - A 2 kg stone is dropped from a 50-m-tall building....Ch. 8 - Prob. 45PCh. 8 - A 1200 kg station wagon is moving along a straight...Ch. 8 - Walking in a boat. A 45.0 kg woman stands up in a...Ch. 8 - A small rocket burns 0.0500 kg of fuel per second,...Ch. 8 - A rocket is fired in deep space, where gravity is...Ch. 8 - A rocket is fired in deep space, where gravity is...Ch. 8 - A 70 kg astronaut floating in space in a 110 kg...Ch. 8 - In 1.00 second an automatic paintball gun can fire...Ch. 8 - In a volcanic eruption, a 2400-kg boulder is...Ch. 8 - A 0.4 kg stone is thrown horizontally at a speed...Ch. 8 - A stone with a mass of 0.100 kg rests on a...Ch. 8 - A steel ball with a mass of 40.0 g is dropped from...Ch. 8 - A movie stuntman (mass 80.0 kg) stands on a window...Ch. 8 - Tennis, anyone? Tennis players sometimes leap into...Ch. 8 - A mass m is placed at the rim of a frictionless...Ch. 8 - Two identical 1.50 kg masses are pressed against...Ch. 8 - A rifle bullet with mass 8.00 g strikes and embeds...Ch. 8 - A 5.00 g bullet traveling horizontally at 450 m/s...Ch. 8 - The objects in Figure 8.49 are constructed of...Ch. 8 - Changing mass. A railroad hopper car filled with...Ch. 8 - Forensic science. Forensic scientists can measure...Ch. 8 - A 2.0 kg steel sphere is hanging from a hook by a...Ch. 8 - A blue puck with mass 0.0400 kg, sliding with a...Ch. 8 - The structure of the atom. During 19101911, Sir...Ch. 8 - Rocket failure! Just as it has reached an upward...Ch. 8 - In a common physics demonstration, two identical...Ch. 8 - A 7.0 kg shell at rest explodes Into two...Ch. 8 - A 15.0 g acorn falls from rest from the top of a...Ch. 8 - Accident analysts. A 1500 kg sedan goes through a...Ch. 8 - A block of clay is suspended as part of a...Ch. 8 - Momentum and the archerfish. Archerfish are...Ch. 8 - Momentum and the archerfish. Archerfish are...Ch. 8 - Momentum and the archerfish. Archerfish are...Ch. 8 - BIO Momentum and the archerfish. Archerfish are...
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