Conceptual Physical Science (6th Edition)
6th Edition
ISBN: 9780134060491
Author: Paul G. Hewitt, John A. Suchocki, Leslie A. Hewitt
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 3, Problem 116E
In the pulley system shown, Block A has a mass of 10 kg and is suspended precariously at rest. Assume that the pulleys and string are massless and there is no friction. No friction means that the tension in one part of the supporting string is the same as in any other part. Discuss why the matt of Block B is 20 kg.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
An aluminum block of mass m, = 4.20 kg and a copper block of mass m, = 8.30 kg are connected by a light string over a frictionless pulley. They sit on a steel surface as shown in the figure below, where e = 32.5°. (See this table for the appropriate coefficients of
friction).
Aluminum
Copper
Steel
(a) When they are released from rest, will they start to move?
O Yes
O No
(b) If the blocks move, determine the magnitude of their acceleration. (If the blocks do not move, enter 0.)
|m/s²
(c) If the blocks move, determine the magnitude of the tension in the string. (If the blocks do not move, enter 0.)
A desperate hiker has to think fast to help his friend who has fallen below him. Quickly, he ties a rope to a rock of mA = 405 kg
and makes his way over the ledge (see the figure below). If the coefficient of static friction between the rock and the ground is
H=0.348, and the mass of the hiker is ma= 70.1 kg, what is the maximum mass of the friend, mc, that the rock can hold so the
hikers can then make their way up over the ledge? Assume the rope is parallel to the ground and the point where the rope
passes over the ledge is frictionless. (ANS: 70.8 kg)
Two blocks, A and B (with mass 50 kg and 100 kg, respectively), are connected by a cord, as
shown in Figure. The pulley has a negligible mass. The coefficient of kinetic friction between
block A and the incline is = 0.11. The bloc B is maintained at rest at a height of 4 m, and the
angle of the incline is 37°. The support of bloc B is removed and B starts to go down.
woCalculate the velocity of the bloc B as it hits the ground.
50 kg
377
100 kg
Chapter 3 Solutions
Conceptual Physical Science (6th Edition)
Ch. 3 - Which has greater momentum: an automobile at rest...Ch. 3 - When a ball is hit with a given force, why does...Ch. 3 - Why is it a good idea to extend your bare hand...Ch. 3 - Why is it poor judgment to have the back of your...Ch. 3 - Why is it advantageous, in karate, to apply a...Ch. 3 - Prob. 6RCQCh. 3 - If a ball has the same speed just before being...Ch. 3 - In which of cases (1), (2), and (3) in Question 7...Ch. 3 - What does it mean to say that momentum (or any...Ch. 3 - When a cannonball is fired, momentum is conserved...
Ch. 3 - Railroad car A rolls at a certain speed and makes...Ch. 3 - If the equally massive railroad cars of Question...Ch. 3 - When is energy most evident?Ch. 3 - Cite an example in which a force is exerted on an...Ch. 3 - Which requires more work: lifting a 50-kg sack a...Ch. 3 - A car is raised a certain distance in a service...Ch. 3 - Two cars are raised to the same elevation on...Ch. 3 - If a moving car speeds up until it is going three...Ch. 3 - What is the relationship between work and power?Ch. 3 - What is the relationship between the gain in...Ch. 3 - Compared with the work that the brakes must supply...Ch. 3 - What will be the kinetic energy of the ram of a...Ch. 3 - An apple hanging from a limb has potential energy...Ch. 3 - Can a machine multiply input force? Input...Ch. 3 - If a machine multiplies force by a factor of 4,...Ch. 3 - What is the efficiency of a machine that...Ch. 3 - What becomes of energy when efficiency is lowered...Ch. 3 - What is the ultimate source of the energy supplied...Ch. 3 - What is the ultimate source of geothermal energy?Ch. 3 - Can we correctly say that hydrogen is a relatively...Ch. 3 - Show that the momentum for a 2-kg brick...Ch. 3 - Show that the impulse on a baseball that is hit...Ch. 3 - Show that when a 10-kg cart undergoes a 2.0-m/s...Ch. 3 - Show that when an impulse produced by a 12-N force...Ch. 3 - Show that 2.4 J of work is done when a force of...Ch. 3 - Calculate the work done when a 20-N force pushes a...Ch. 3 - Show that when a 3.0-kg book is lifted 2.0 m, its...Ch. 3 - Show that the gravitational potential energy of a...Ch. 3 - Show that the kinetic energy of a 1.0-kg book...Ch. 3 - Calculate the kinetic energy of a 84-kg scooter...Ch. 3 - Show that 24 J of work is done when a 3.0-kg block...Ch. 3 - Show that a 2,500,000-J change in kinetic energy...Ch. 3 - Show that 50 W of power is required to give a...Ch. 3 - Show that nearly 786 W of power is expended when a...Ch. 3 - Show that the efficiency of a machine that has an...Ch. 3 - In Chapter 1 we learned that acceleration a=vt,...Ch. 3 - A 10-kg bag of groceries is tossed onto a table at...Ch. 3 - An ostrich egg of mass m is tossed at a speed v...Ch. 3 - A 6-kg bail rolling at 3 m/s bumps into a pillow...Ch. 3 - At a baseball game, a ball of mass m = 0.15 kg...Ch. 3 - Jeannie Beanie (mass 40 kg), standing on slippery...Ch. 3 - A railroad diesel engine weighs four times as much...Ch. 3 - A 5-kg fish swimming at 1 m/s swallows an...Ch. 3 - Little Hudson (next page) holds the 10-kgbarbell...Ch. 3 - It you push a crate horizontally with a force of...Ch. 3 - A simple lever is used to lift a heavy load. When...Ch. 3 - The following questions refer to Problem 60: (a)...Ch. 3 - In raising a 6000-N piano with a pulley system,...Ch. 3 - The girl steadily pulls her end of the rope upward...Ch. 3 - How many watts of power do you expend when you...Ch. 3 - Show that 480 W of power is expended by a...Ch. 3 - When an average force F is exerted over a certain...Ch. 3 - Emily holds a banana of mass m over the edge of a...Ch. 3 - Starting from rest, Megan Zooms down a...Ch. 3 - The balls have different masses and speeds. Rank...Ch. 3 - Jogging Jake runs along a train flatcar that moves...Ch. 3 - Starting from rest, Marshall pushes crates across...Ch. 3 - A ball is released from rest at the left of the...Ch. 3 - The roller coaster ride starts from rest at point...Ch. 3 - Rank the scale readings from greatest to least....Ch. 3 - A lunar vehicle is tested on Earth at a speed of...Ch. 3 - In terms of impulse and momentum, why do airbags...Ch. 3 - Why are todays autos designed to crumple upon...Ch. 3 - If you throw a raw egg against a wall, youll break...Ch. 3 - In terms of impulse and momentum, when a boxer is...Ch. 3 - To throw a ball, do you exert an impulse on it? Do...Ch. 3 - Bronco dives from a hovering helicopter and finds...Ch. 3 - A pair of skaters who are initially at rest push...Ch. 3 - When you are traveling in your car at highway...Ch. 3 - You are at the front of a floating canoe near a...Ch. 3 - If you throw a ball horizontally while standing on...Ch. 3 - A fully dressed person is at rest in the middle of...Ch. 3 - Prob. 87ECh. 3 - In the previous chapter, rocket propulsion was...Ch. 3 - When vertically falling sand lands in a...Ch. 3 - In a movie, the hero jumps straight down from a...Ch. 3 - Freddy Frog drops vertically from a tree onto a...Ch. 3 - If your friend pushes a stroller four times as far...Ch. 3 - Which requires more work: stretching a strong...Ch. 3 - Two people of the same weight climb a flight of...Ch. 3 - Why do you run out of breath when running up the...Ch. 3 - A friend says that when twice as much works is...Ch. 3 - Compared with a pickup truck moving at a certain...Ch. 3 - When a cannon with a long barrel is fired, the...Ch. 3 - At what point in its motion is the KE of a...Ch. 3 - A physics instructor demonstrates energy...Ch. 3 - On a playground slide, a child has potential...Ch. 3 - Consider the identical balls released from rest on...Ch. 3 - Prob. 103ECh. 3 - In the absence of air resistance, a snowball...Ch. 3 - Youre on a rooftop and you throw one snowball...Ch. 3 - When a driver applies the brakes 10 keep a car...Ch. 3 - When the mass of a moving object is doubled, with...Ch. 3 - When the velocity of an object it doubled, by what...Ch. 3 - Which, if either, has greater momentum a 1-kg ball...Ch. 3 - If an objects kinetic energy is zero, what is its...Ch. 3 - If your momentum is zero, is your kinetic energy...Ch. 3 - Two lumps of clay with equal and opposite momenta...Ch. 3 - Consider Charlottes swinging-balls apparatus. If...Ch. 3 - Discuss the physics that explains how the girl in...Ch. 3 - Why bother using a machine if it cannot multiply...Ch. 3 - In the pulley system shown, Block A has a mass of...Ch. 3 - If an automobile had a 100% efficient engine,...Ch. 3 - The energy we need to live comes from chemically...Ch. 3 - To combat wasteful habits, we often speak of...Ch. 3 - What is the argument that dry-rock geothermal...Ch. 3 - What is the argument that the energy provided by a...Ch. 3 - What is the fuel that power a fuel cell in...Ch. 3 - Prob. 123ECh. 3 - Railroad cars are loosely coupled so that there is...Ch. 3 - Your friend says that the law of momentum...Ch. 3 - An ice sailcraft is stalled on a frozen lake on a...Ch. 3 - Will your answer to Question 126 be different if...Ch. 3 - Discuss the advisability of simply removing the...Ch. 3 - Suppose that three astronauts outside a spaceship...Ch. 3 - Discuss whether something can have energy without...Ch. 3 - Arrange the following four energy-transforming...Ch. 3 - What are the roles of water, energy, hydrogen, and...Ch. 3 - Does a car burn more fuel when its lights are...Ch. 3 - This may seem like an easy question for a physics...Ch. 3 - Your friend says that one way to improve air...Ch. 3 - Does the electric power produced by wind-powered...Ch. 3 - A red ball of mass m and a blue ball of mass 2m...Ch. 3 - No work is done by gravity on a bowling ball...Ch. 3 - Consider a bob attached by a stringa simple...Ch. 3 - Consider a satellite in a circular orbit above...Ch. 3 - A freight train rolls along a track with...Ch. 3 - In the absence of external forces, momentum is...Ch. 3 - If the running speed of Fast Freda doubles, what...Ch. 3 - Which of the following equations best illustrate s...Ch. 3 - Which of the following equations is most useful...Ch. 3 - How much work is done on a 200-kg crate that is...Ch. 3 - A circus diver drops from a high pole into water...Ch. 3 - A bicycle that travels twice as fast as another...Ch. 3 - A bicycle that travels twice as fast as another...Ch. 3 - A machine cannot multiply (a) force. (b) distance....
Additional Science Textbook Solutions
Find more solutions based on key concepts
3. What is free-fall, and why does it make you weightless? Briefly describe why astronauts are weightless in th...
The Cosmic Perspective
A proton is at the origin and an ion is at x = 5.0 nm. If the electric field is zero at x = 5.0nm, whats the io...
Essential University Physics (3rd Edition)
Express the unit vectors in terms of (that is, derive Eq. 1.64). Check your answers several ways Also work o...
Introduction to Electrodynamics
21.30 (a) Calculate the magnitude and direction (relative to the +.x-axis) of the electric field in Example 21....
University Physics (14th Edition)
The radiation pressure exerted by the beam of light on the tooth.
Physics (5th Edition)
47. A block hangs in equilibrium from a vertical spring. When a second identical block is added, the original ...
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- Jamal and Dayo are lifting a large chest, weighing 207 lb, by using the two rope handles attached to either side. As they lift and hold it up so that it is motionless, each handle makes a different angle with respect to the vertical side of the chest (Fig. P5.76). If the angle between Jamals handle and the vertical side is 25.0 and the angle between Dayos handle and the vertical side of the chest is 30.0, what are the tensions in each handle? FIGURE P5.76arrow_forwardFigure 4 shows a block-pulley system to lift heavy objects. Box mı, of mass 10.0 kg, rests on a surface inclined at e =25 °to the horizontal. It is connected by a lightweight cord, which passes over a massless and frictionless pulley, to a bag of rice, which hangs freely as shown. Given coefficient of static friction, 4; and coefficient of kinetic friction, g are 0.40 and 0.15, respectively. mi Figure 4arrow_forwardA 80.0 kg mail bag hangs by a vertical rope 3.5 m long. A postal worker then displaces the bag to a position 2.4 m sideways from its original position, always keeping the rope taut.arrow_forward
- A block of mass m resting on a 20 degree slope. The block has coefficients of friction us = .64 and uk = .54 with the surface of the slope. It is connected using a very light string over an ideal pulley to a hanging block of mass 2 kg. The string above the slope pulls parallel to the surface. What is the minimum mass m so the system will remain at the rest when it is released from rest?arrow_forwardA 5 kg box rests on a tabletop. On one side, it compresses a spring with a stiffness of 1000 N/m by 1 cm. If the friction force cancels out the force of the spring what must be the minimum coefficient of static friction between the box and table to keep the box from moving?arrow_forwardThe slope of the 4.1 kN force F is specified as shown in the figure. Express F as a vector in terms of the unit vectors i and j. Assume a = 9, b = 3. Answer: F = (i it i j) KNarrow_forward
- A gymnast with mass mG = 50.0 kg suspends herself from the lowerend of a hanging rope of negligible mass. The upper end of the rope isattached to the gymnasium ceiling. What is the gymnast’s weight?arrow_forwardan old rope can only safely suspend 120 kg. The old rope losses 20 kg of holding strength perminute once it’s under tension from any thing over 80 kg. When the rope is tied to a beam, it hangs down with a vertical length of 12.0 m. Calculate the minimum time required for a 85 kg person starting from rest to climb the entire length of the rope without breaking it.arrow_forwardThe weightless strut in the figure below is not attached to the wall; it is prevented from falling only by friction. (Let w = 365 N, L = 4.45 m and h = 2.95 m.) (a) Find the magnitude of the force of friction between the wall and the strut.(b) Find the normal force exerted by the wall on the strut.(c) Find the minimum coefficient of static friction.arrow_forward
- A block of mass 2.00 kg starts from rest at the edge of the ramp as shown. It is pushed up the ramp by a 30.0 N force, F, acting parallel to the ramp as shown. The ramp makes an angle of 40.0° with the horizontal. Assume the ramp is smooth. When the block reaches the top of the ramp, the force F stops acting so that the block is only under the influence of gravity. It takes the block t=5 seconds to reach point A. The block is therefore launched from the top of the ramp and follows a parabolic trajectory in the air. Take the acceleration due to Earth's gravity to be 9.81 m/s². 40- How much time (measured starting at point A) does it take for the block to travel from the edge of the ramp (point A) to the top of its trajectory (point B)? Clearly show all work and steps.arrow_forwardShow the complete solutionarrow_forwardConsider the Atwood machine shown in the figure, where m, = 2.00 kg and m, = 7.65 kg. The system starts at rest, then the sphere is given a quick push downward, giving it an initial speed of 2.35 m/s. Assume the pulley and cord are massless, and the cord is inextensible. Neglect friction. (a) Through what distance (in m) will m, descend? (b) What is the velocity (in m/s) of m, after 1.80 s? magnitude m/s direction ---Select---arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
General Relativity: The Curvature of Spacetime; Author: Professor Dave Explains;https://www.youtube.com/watch?v=R7V3koyL7Mc;License: Standard YouTube License, CC-BY