All Matches

Solution Library

Expert Answer

Textbooks

Search Textbook questions, tutors and Books

Oops, something went wrong!

Change your search query and then try again

Result Not Found

Books FREE
Tutors
Study Help
Ask a Question

Search
Sign In
Register

study help
sciences
the physical universe

Questions and Answers of The Physical Universe

In 2100 the number of people in the world is predicted to reach at leasta. 1 billionb. 2.5 billionc. 7 billiond. 9.6 billion
What are the three main factors that will require changes in today’s patterns of energy production and consumption?
Approximately 5.4 × 106 J of chemical energy is released when 1 kg of dynamite explodes. What fraction of the total energy of the dynamite is this?
One kilogram of water at 0°C contains 335 kJ of energy more than 1 kg of ice at 0°C. What is the mass equivalent of this amount of energy?
What is the effect on the law of conservation of energy of the discovery that matter and energy can be converted into each other?
Why is it impossible for an object to move faster than the speed of light?
The length of a rod is measured by several observers, one of whom is stationary with respect to the rod. What must be true of the value obtained by the stationary observer?
The theory of relativity predicts a variety of effects that disagree with our everyday experience. Why do you think this theory is universally accepted by scientists?
As the polar ice caps melt, the length of the day increases. Why?
The 176-g head of a golf club is moving at 45 m/s when it strikes a 46-g golf ball and sends it off at 65 m/s. Find the final speed of the clubhead after the impact, assuming that the mass of the
A 30-kg girl who is running at 3 m/s jumps on a stationary 10-kg sled on a frozen lake. How fast does the sled with the girl on it then move?
An empty dump truck coasts freely with its engine off along a level road. (a) What happens to the truck’s speed if rain starts to fall and water collects in it? (b) The rain stops and the
A ball of mass m rolling on a smooth surface collides with a stationary ball of mass M. (a) Under what circumstances will the first ball come to a stop while the second ball moves off?(b) Under
When the kinetic energy of an object is doubled, what happens to its momentum?
What happens to the momentum of a car when it comes to a stop?
An 800-kg car coasts down a hill 40 m high with its engine off and the driver’s foot pressing on the brake pedal. At the top of the hill the car’s speed is 6 m/s and at the bottom it is 20 m/s.
In an effort to lose weight, a person runs 5 km per day at a speed of 4 m/s. While running, the person’s body processes consume energy at a rate of 1.4 kW. Fat has an energy content of about 40
The human forearm is a class III lever. Find the force the biceps muscle of an upper arm must develop to lift further a 5-kg dumbbell held in the hand of a person whose forearm is horizontal. How
The lightest particle in an atom is an electron, whose rest mass is 9.1 × 10-31 kg. The energy equivalent of this mass is approximatelya. 10-13 Jb. 10-15 Jc. 3 × 10-23 Jd. 10-47 J
A person uses a force of 49 N to raise a 30-kg load by 1.5 m with a pulley system. How much rope did she pull through the system?
The smallest part of the total energy of the ball of Multiple Choice 30 isa. kinetic energyb. potential energy relative to the groundc. rest energyd. momentum
An object has a rest energy of 1 J when its mass isa. 1.1 × 10-17 kgb. 3.3 × 10-9 kgc. 1 kgd. 9 × 1016 kg
A skier is sliding downhill at 8 m/s when she reaches an icy patch on which her skis move freely with negligible friction. The difference in altitude between the top of the icy patch and its bottom
A 30-kg girl and a 25-kg boy are standing on frictionless roller skates. The girl pushes the boy, who moves off at 1.0 m/s. The girl’s speed isa. 0.45 m/sb. 0.55 m/sc. 0.83 m/sd. 1.2 m/s
A 10,000-kg freight car moving at 2 m/s collides with a stationary 15,000-kg freight car. The two cars couple together and move off ata. 0.8 m/sb. 1 m/sc. 1.3 m/sd. 2 m/s
A ball is dropped from a height of 1 m and loses 10 percent of its kinetic energy when it bounces on the ground. To what height does it then rise?
A 1-kg ball is thrown in the air. When it is 10 m above the ground, its speed is 3 m/s. At this time most of the ball’s total energy is in the form ofa. kinetic energyb. potential energy relative
A person uses a force of 300 N to pry up one end of a 120-kg box using a lever 2.4 m long. The distance from the end of the box to the fulcrum isa. 40 cmb. 49 cmc. 81 cmd. 171 cm
Two identical balls move down a tilted board. Ball A slides down without friction and ball B rolls down. Which ball reaches the bottom first? Why?
A machine has a MA of 6.0. The work input needed by the machine to raise a 40-kg load by 3.0 m isa. 0.12 kJb. 0.20 kJc. 1.2 kJd. 7.1 kJ
The highest MA that can be obtained by a system of two pulleys isa. 2b. 3c. 4d. 5
Why does a nail become hot when it is hammered into a piece of wood?
The 2-kg blade of an ax is moving at 60 m/s when it strikes a log. If the blade penetrates 2 cm into the log as its KE is turned into work, the average force it exerts is a. 3 kNb. 90 kNc. 72
A 1-kg object has kinetic energy of 1 J when its speed isa. 0.45 m/sb. 1 m/sc. 1.4 m/sd. 4.4 m/s
A 1-kg object has a potential energy of 1 J relative to the ground when it is at a height ofa. 0.102 mb. 1 mc. 9.8 md. 98 m
Does every moving body possess kinetic energy? Does every stationary body possess potential energy?
Car A has a mass of 1000 kg and is moving at 60 km/h. Car B has a mass of 2000 kg and is moving at 30 km/h. The kinetic energy of car A isa. half that of car Bb. equal to that of car Bc. twice that
How long will it take a 1000-kg car with a power output of 20 kW to go from 10 m/s to 20 m/s?
A 40-kg boy runs up a flight of stairs 4 m high in 4 s. His power output isa. 160 Wb. 392 Wc. 40 Wd. 1568 W
A 150-kg yak has an average power output of 120 W. The yak can climb a mountain 1.2 km high ina. 25 minb. 4.1 hc. 13.3 hd. 14.7 h
A 1-kg salmon is hooked by a fisherman and it swims off at 2 m/s. The fisherman stops the salmon in 50 cm by braking his reel. How much average force does the fishing line exert on the fish?
The work a 300-W electric grinder can do in 5.0 min isa. 1 kJb. 1.5 kJc. 25 kJd. 90 kJ
A total of 4900 J is used to lift a 50-kg mass. The mass is raised to a height ofa. 10 mb. 98 mc. 960 md. 245 km
A moving object whose initial KE is 10 J is subject to a frictional force of 2 N that acts in the opposite direction. How far will the object move before coming to a stop?
The work done in lifting 30 kg of bricks to a height of 20 m isa. 61 Jb. 600 Jc. 2940 Jd. 5880 J
The work done in holding a 50-kg object at a height of 2 m above the floor for 10 s isa. 0b. 250 Jc. 1000 Jd. 98,000 J
Which of these energies might correspond to the KE of a person riding a bicycle on a road: 10 J; 1 kJ; 100 kJ?
Albert Einstein did not discover thata. the length of a moving object is less than its length at restb. the acceleration of gravity g is a universal constantc. light is affected by gravityd. gravity
It is not true thata. light is affected by gravityb. the mass of a moving object depends upon its speedc. the maximum speed anything can have is the speed of lightd. momentum is a form of energy
A crane whose motor has a power input of 5.0 kW lifts a 1200-kg load of bricks through a height of 30 m in 90 s. Find the efficiency of the crane, which is the ratio between its output power and its
The upper limit to the speed of an object with massa. depends on the massb. corresponds to a KE equal to its rest energyc. is the speed of soundd. is the speed of light
A spacecraft has left the earth and is moving toward Mars. An observer on the earth finds that, relative to measurements made when the spacecraft was at rest, itsa. length is shorterb. KE is less
A 700-kg horse whose power output is 1.0 hp is pulling a sled over the snow at 3.5 m/s. Find the force the horse exerts on the sled.
The formula 1_2 mv2 for kinetic energya. is the correct formula if v is properly interpretedb. always gives too high a valuec. is the low-speed approximation to the correct formulad. is the
According to the principle of relativity, the laws of physics are the same in all frames of referencea. at rest with respect to one anotherb. moving toward or away from one another at constant
A weightlifter raises a 70-kg barbell from the floor to a height of 2.2 m in 1.2 s. What was his average power output during the lift?
A spinning skater whose arms are at her sides then stretches out her arms horizontally.a. She continues to spin at the same rateb. She spins more rapidlyc. She spins more slowlyd. Any of the choices
The operation of a rocket is based upona. pushing against its launching padb. pushing against the airc. conservation of linear momentumd. conservation of angular momentum
The motor of a boat develops 60 kW when the boat’s speed is 15 km/h. With how much force does the water resist the motion of the boat?
A bomb dropped from an airplane explodes in midair.a. Its total kinetic energy increases.b. Its total kinetic energy decreases.c. Its total momentum increases.d. Its total momentum decreases.
Two balls, one of mass 5 kg and the other of mass 10 kg, are dropped simultaneously from a window. When they are 1 m above the ground, the balls have the samea. kinetic energyb. potential energyc.
The acceleration of gravity on the surface of Mars is 3.7 m/s2. If an astronaut in a space suit can jump upward 20 cm on the earth’s surface, how high could he jump on the surface of Mars?
When the speed of a moving object is halved,a. its KE is halvedb. its PE is halvedc. its rest energy is halvedd. its momentum is halved
The total amount of energy (including the rest energy of matter) in the universea. cannot changeb. can decrease but not increasec. can increase but not decreased. can either increase or decrease
A total of 490 J of work is needed to lift a body of unknown mass through a height of 10 m. What is its mass?
When the momentum of a moving object is increased, there must also be an increase in which one or more of the following of the object’s properties?a. speedb. accelerationc. kinetic energyd.
A moving object must have which one or more of the following?a. potential energyb. kinetic energyc. rest energyd. momentum
The sun exerts a gravitational force of 4.0 × 1028 N on the earth, and the earth travels 9.4 × 1011 m in its yearly orbit around the sun. How much work is done by the sun on the earth each year?
An object at rest may havea. velocityb. momentumc. kinetic energyd. potential energy
Which of the following is not a unit of work?a. newton-meterb. joulec. kilogram-meterd. watt-hour
A person holds a 10-kg package 1.2 m above the floor for 1 min. How much work is done?
Is an astronaut in an orbiting spacecraft actually “weightless”?
An airplane makes a vertical circle in which it is upside down at the top of the loop. Will the passengers fall out of their seats if there is no belt to hold them in place?
A dishonest grocer installs a 100-kg lead block under the pan of his scale. How much gravitational force does the lead exert on 2 kg of cheese placed on the pan if the centers of mass of the lead and
According to Kepler’s second law, the earth travels fastest when it is closest to the sun. Is this consistent with the law of gravitation? Explain.
Is the sun’s gravitational pull on the earth the same at all seasons of the year? Explain.
Compare the weight and mass of an object at the earth’s surface with what they would be at an altitude of two earth’s radii.
A track team on the moon could set new records for the high jump or pole vault (if they did not need space suits, of course) because of the smaller gravitational force. Could sprinters also improve
The 200-g head of a golf club moves at 40 m/s in a circular arc of 1.2 m radius. How much force must the player exert on the handle of the club to prevent it from flying out of her hands at the
Find the minimum radius at which an airplane flying at 300 m/s can make a U-turn if the centripetal force on it is not to exceed 4 times the airplane’s weight.
A 40-kg crate is lying on the flat floor of a truck moving at 15 m/s. A force of 150 N is needed to slide the crate against the friction between the bottom of the crate and the floor. What is the
A car makes a clockwise turn on a level road at too high a speed and overturns. Do its left or right wheels leave the road first?
Under what circumstances, if any, can something move in a circular path without a centripetal force acting on it?
When a 5-kg rifle is fired, the 9-g bullet is given an acceleration of 30 km/s while it is in the barrel.(a) How much force acts on the bullet?(b) Does any force act on the rifle? If so, how much and
An engineer designs a propeller-driven spacecraft. Because there is no air in space, the engineer includes a supply of oxygen as well as a supply of fuel for the motor. What do you think of the idea?
A book rests on a table. (a) What is the reaction force to the force the book exerts on the table? (b) To the force gravity exerts on the book?
Since the opposite forces of the third law of motion are equal in magnitude, how can anything ever be accelerated?
A person stands on a scale in an elevator. When the elevator is at rest, the scale reads 700 N. When the elevator starts to move, the scale reads 600 N.(a) Is the elevator going up or down?(b) Is it
A parachutist whose total mass is 100 kg is falling at 50 m/s when her parachute opens. Her speed drops to 6 m/s in 2 s. What is the total force her harness had to withstand? How many times her
An 80-kg man slides down a rope at constant speed. (a) What is the minimum breaking strength the rope must have? (b) If the rope has precisely this strength, will it support the man if he
A person weighs 85 N on the surface of the moon and 490 N on the surface of the earth. What is the acceleration of gravity on the surface of the moon?
Consider the statement: Sara weighs 55 kg. What is wrong with the statement? Give two ways to correct it.
A car and driver with a total mass of 1600 kg has a maximum acceleration of 1.2 m/s2. If the car picks up three 80-kg passengers, what is its maximum acceleration now?
A man whose weight is 800 N on the earth’s surface is also in the spacecraft of Multiple Choice 47. His weight there isa. 200 Nb. 400 Nc. 800 Nd. 1600 N
A woman whose mass is 60 kg on the earth’s surface is in a spacecraft at an altitude of one earth’s radius above the surface. Her mass there isa. 15 kgb. 30 kgc. 60 kgd. 120 kg
A bicycle and its rider together have a mass of 80 kg. If the bicycle’s speed is 6 m/s, how much force is needed to bring it to a stop in 4 s?
If the earth were 3 times as far from the sun as it is now, the gravitational force exerted on it by the sun would bea. 3 times as large as it is nowb. 9 times as large as it is nowc. one-third as
A 1200-kg car whose speed is 6 m/s rounds a turn whose radius is 30 m. The centripetal force on the car isa. 48 Nb. 147 Nc. 240 Nd. 1440 N
The brakes of a 1200-kg car exert a force of 4 kN. How long will it take for them to slow the car to a stop from an initial speed of 24 m/s?
A car rounds a curve at 20 km/h. If it rounds the curve at 40 km/h, its tendency to overturn is a. halvedb. doubledc. tripledd. quadrupled

Showing 1500 - 1600 of 1951

First
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

Get In Touch

About Us
Contact Us
Career
Jobs
FAQ
Campus Ambassador

Company Info

Security
Copyrights
Privacy Policy
Terms & Condition
SolutionInn Fee
Scholarship

Services

Sitemap
Fun
Definitions
Become Tutor
Study Help Categories
Recent Questions
Expert Questions

Copyright © 2024 SolutionInn All Rights Reserved.

Get the SolutionInn - Study Help App