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
Toggle navigation
FREE Trial
S
Books
FREE
Tutors
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Ask a Question
Search
Search
Sign In
Register
study help
sciences
the physical universe
Questions and Answers of
The Physical Universe
The radius of the circle in which an object is moving at constant speed is doubled. The required centripetal force isa. one-quarter as great as beforeb. one-half as great as beforec. twice as great
In accelerating from a standing start to a speed of 300 km/h (186 mi/h—not its top speed!), the 1900-kg Bugatti Veyron sports car exerts an average force on the road of 9.4 kN. How long does the
The upward force the rope of a hoist must exert to raise a 400-kg load of bricks with an acceleration of 0.4 m/s2 isa. 160 Nb. 1568 Nc. 3760 Nd. 4080 N
An upward force of 600 N acts on a 50-kg dumbwaiter. The dumbwaiter’s acceleration isa. 0.82 m/s2b. 2.2 m/s2c. 11 m/s2d. 12 m/s2
A person at the masthead of a sailboat moving at constant speed in a straight line drops a wrench. The masthead is 20 m above the boat’s deck and the stern of the boat is 10 m behind the mast. Is
A salami weighs 3 lb. Its mass isa. 0.31 kgb. 1.36 kgc. 6.6 kgd. 29.4 kg
The weight of 400 g of onions isa. 0.041 Nb. 0.4 Nc. 3.9 Nd. 3920 N
A bullet is fired horizontally from a rifle at 200 m/s from a cliff above a plain below. The bullet reaches the plain 5 s later.(a) How high was the cliff?(b) How far from the cliff did the bullet
A bicycle and its rider together have a mass of 80 kg. If the bicycle’s speed is 6 m/s, the force needed to bring it to a stop in 4 s isa. 12 Nb. 53 Nc. 120 Nd. 1176 N
A 300-g ball is struck with a bat with a force of 150 N. If the bat was in contact with the ball for 0.020 s, the ball’s speed is a. 0.01 m/sb. 0.1 m/sc. 2.5 m/sd. 10 m/s
A car whose mass is 1600 kg (including the driver) has a maximum acceleration of 1.20 m/s2. When a certain passenger is also in the car, its maximum acceleration becomes 1.13 m/s2. The mass of the
When a net force of 1 N acts on a 1-N body, the body receivesa. a speed of 1 m/sb. an acceleration of 0.1 m/s2c. an acceleration of 1 m/s2d. an acceleration of 9.8 m/s2
A ball is thrown vertically upward with an initial speed of 30 m/s. (a) How long will it take the ball to reach the highest point in its path?(b) How long will it take the ball to return to its
When a net force of 1 N acts on a 1-kg body, the body receivesa. a speed of 1 m/sb. an acceleration of 0.1 m/s2c. an acceleration of 1 m/s2d. an acceleration of 9.8 m/s2
A bottle falls from a blimp whose altitude is 1200 m. If there was no air resistance, the bottle would reach the ground ina. 5 sb. 11 sc. 16 sd. 245 s
A ball is thrown upward from the edge of a cliff with an initial speed of 6 m/s.(a) How fast is it moving 0.5 s later? In what direction? (b) How fast is it moving 2 s later? In what direction?
The distance the car in Multiple Choice 31 travels before it comes to a stop isa. 6.5 mb. 8.3 mc. 21 md. 42 m
A car with its brakes applied has an acceleration of –1.2 m/s2.If its initial speed is 10 m/s, the distance the car covers in the first 5 s after the acceleration begins isa. 15 mb. 32 mc. 35 md.
A ball is thrown downward at 12 m/s. What is its speed 1.0 s later?
A car traveling at 10 m/s begins to be accelerated at 12 m/s2.The distance the car covers in the first 5 s after the acceleration begins isa. 60 mb. 80 mc. 150 md. 200 m
A car that starts from rest has a constant acceleration of 4 m/s2. In the first 3 s the car travelsa. 6 mb. 12 mc. 18 md. 172 m
A person dives off the edge of a cliff 33 m above the surface of the sea below. Assuming that air resistance is negligible, how long does the dive last and with what speed does the person enter the
A ball is thrown upward at a speed of 12 m/s. It will reach the top of its path in abouta. 0.6 sb. 1.2 sc. 1.8 sd. 2.4 s
How long does a car whose acceleration is 2 m/s2 need to go from 10 m/s to 30 m/s?a. 10 sb. 20 sc. 40 sd. 400 s
A person in a stationary elevator drops a coin and the coin reaches the floor of the elevator 0.6 s later. Would the coin reach the floor in less time, the same time, or more time if it were dropped
A ship travels 200 km to the south and then 400 km to the west. The ship’s displacement from its starting point isa. 200 kmb. 400 kmc. 450 kmd. 600 km
A stone is thrown horizontally from a cliff and another, identical stone is dropped from there at the same time. Do the stones reach the ground at the same time? How do their speeds compare when they
An airplane whose airspeed is 200 km/h is flying in a wind of 80 km/h. The airplane’s speed relative to the ground is betweena. 80 and 200 km/hb. 80 and 280 km/hc. 120 and 200 km/hd. 120 and 280
Which one or more of the following sets of displacements might be able to return a car to its starting point?a. 5, 5, and 5 kmb. 5, 5, and 10 kmc. 5, 10, and 10 kmd. 5, 5, and 20 km
A bicycle travels 12 km in 40 min. Its average speed isa. 0.3 km/hb. 8 km/hc. 18 km/hd. 48 km/h
An astronaut inside an orbiting satellite feels weightless becausea. He or she is wearing a space suitb. The satellite is falling toward the earth just as fast as the astronaut is, so there is no
A rifle is aimed directly at a squirrel in a tree. Should the squirrel drop from the tree at the instant the rifle is fired or should it remain where it is? Why?
The speed needed to put a satellite in orbit does not depend ona. the mass of the satelliteb. the radius of the orbitd. the value of g at the orbitc. the shape of the orbit
Is it true that something dropped from rest falls three times farther in the second second after being let go than it does in the first second?
The gravitational force with which the earth attracts the moon a. is less than the force with which the moon attracts the earthb. is the same as the force with which the moon attracts the
A car starts from rest and covers 400 m (very nearly _14 mi) in 20 s. Find the average acceleration of the car and its final speed.
The centripetal force that keeps the earth in its orbit around the sun is provideda. by inertiab. by the earth’s rotation on its axisc. partly by the gravitational pull of the sund. entirely by the
A car rounds a curve on a level road. The centripetal force on the car is provided bya. inertiab. gravityc. friction between the tires and the roadd. the force applied to the steering wheel
A car is moving at 10 m/s when it begins to be accelerated at 2.5 m/s2. (a) How long does the car take to reach a speed of 25 m/s? (b) How far does it go during this period?
An object is moving in a circle with a constant speed. Its acceleration is constant ina. magnitude onlyb. direction onlyc. both magnitude and directiond. neither magnitude nor direction
In order to cause something to move in a circular path, it is necessary to providea. a reaction forceb. an inertial forcec. a centripetal forced. a gravitational force
A car starts from rest and reaches a speed of 40 m/s in 10 s. If its acceleration remains the same, how fast will it be moving 5 s later?
When a boy pulls a cart, the force that causes him to move forward isa. the force the cart exerts on himb. the force he exerts on the cartc. the force he exerts on the ground with his feetd. the
Compared with her mass and weight on the earth, an astronaut on Venus, where the acceleration of gravity is 8.8 m/s2, hasa. Less mass and less weightb. Less mass and the same weightc. Less mass and
A car that is towing a trailer is accelerating on a level road. The magnitude of the force the car exerts on the trailer isa. Equal to the force the trailer exerts on the carb. Greater than the force
A car whose acceleration is constant reaches a speed of 80 km/h in 20 s starting from rest. How much more time is required for it to reach a speed of 130 km/h?
The earth and the moon exert equal and opposite forces on each other. The force the earth exerts on the moona. is the action forceb. is the reaction forcec. can be considered either as the action or
Can a rapidly moving object have the same acceleration as a slowly moving one?
The weight of an objecta. Is the quantity of matter it containsb. Is the force with which it is attracted to the earthc. Is basically the same quantity as its mass but is expressed in different
If we know the magnitude and direction of the net force on an object of known mass, Newton’s second law of motion lets us find itsa. Positionb. Speedc. Accelerationd. Weight
A woman walks 70 m to an elevator and then rises upward 40 m. What is her displacement from her starting point?
When an object is accelerated,a. its direction never changesb. its speed always increasesc. it always falls toward the earthd. a net force always acts on it
You are riding a bicycle at constant speed when you throw a ball vertically upward. It will landa. In front of youb. On your headc. Behind youd. Any of the above, depending on the ball’s speed
Is it correct to say that scalar quantities are abstract, idealized quantities with no precise counterparts in the physical world, whereas vector quantities properly represent reality because they
The acceleration of a stone thrown upward isa. Greater than that of a stone thrown downwardb. The same as that of a stone thrown downwardc. Less than that of a stone thrown downwardd. Zero until it
Two objects have the same size and shape but one of them is twice as heavy as the other. They are dropped simultaneously from a tower. If air resistance is negligible, a. The heavy object
A woman jogs for 2 km at 8 km/h and then walks for 2 km at 6 km/h. What is her average speed for the entire trip?
In which of the following examples is the motion of the car not accelerated?a. A car turns a corner at the constant speed of 20 km/h.b. A car climbs a steep hill with its speed dropping from 60 km/h
The sum of two vectors is a minimum when the angle between them isa. 0b. 45°c. 90°d. 180°
In 1977 Steve Weldon ate 91 m of spaghetti in 29 s. At the same speed, how long would it take Mr. Weldon to eat 5 m of spaghetti?
A box suspended by a rope is pulled to one side by a horizontal force. The tension in the ropea. Is less than beforeb. Is unchangedc. Is greater than befored. May be any of the above, depending on
Which of the following statements is incorrect?a. All vector quantities have directions.b. All vector quantities have magnitudes.c. All scalar quantities have directions.d. All scalar quantities have
A woman standing before a cliff claps her hands, and 2.8 s later she hears the echo. How far away is the cliff? The speed of sound in air at ordinary temperatures is 343 m/s.
Which of the following quantities is not a vector quantity?a. Velocityb. Accelerationc. Massd. Force
Use the proper number of significant figures to express the values ofa. 6.23 × 107 + 4.71 × 108 + 3.04 × 109b. (9.003 × 103)(2.41 × 104)c. 9.36/4.0
How many microphones are there in a megaphone?
The speedometer of a European car gives its speed in kilometers per hour. What is the car’s speed in miles per hour when the speedometer reads 80?
How many square feet are there in an area of 1.00 square meters? Use the proper number of significant figures in the answer.
The world’s tallest tree is a sequoia in California 368 ft high. How high is this in meters? In kilometers?
In the following pairs of length units, which is the shorter: inch, centimeter? Yard, meter? Mile, kilometer?
The earth takes almost exactly 24 h to make a complete turn on its axis, so we might expect each high tide to occur 12 h after the one before. However, the actual time between high tides is 12 h 25
A person is 180 cm tall. This is equivalent toa. 4 ft 6 in.b. 5 ft 9 in.c. 5 ft 11 in.d. 7 ft 1 in.
What is the difference between spring and neap tides? Under what circumstances does each occur?
Of the following, the shortest isa. 1 mmb. 0.01 in.c. 0.001 md. 0.001 ft
Why is gravity considered a fundamental force whereas the force a bat exerts on a ball is not?
The prefix micro stands fora. 1/10b. 1/100c. 1/1000d. 1/1,000,000
Tides are causeda. Only by the sunb. Only by the moonc. By both the sun and the moond. Sometimes by the sun and sometimes by the moon
The average distance from the earth to the sun is called the astronomical unit (AU). If an asteroid is 4 AU from the sun and its period of revolution around the sun is 8 years, does it obey
The earth bulges slightly at the equator and is flattened at the poles becausea. It spins on its axisb. It revolves around the sunc. Of the sun’s gravitational pulld. Of the moon’s gravitational
Compare the ptolemaic and copernican explanations for(a) The rising and setting of the sun;(b) The eastward drift of the sun relative to the stars that takes a year for a complete circuit;(c) The
According to Kepler’s third law, the time needed for a planet to complete an orbit around the suna. Is the same for all the planetsb. Depends on the planet’s sizec. Depends on the planet’s
What is the basic difference between the ptolemaic and copernican models? Why is the ptolemaic model considered incorrect?
Kepler modified the copernican system by showing that the planetary orbits area. Ellipsesb. Circlesc. Combinations of circles forming looped orbitsd. The same distance apart from one another
From observations of the moon, why would you conclude that it is a relatively small body revolving around the earth rather than another planet revolving around the sun?
What must be your location if the stars move across the sky in circles centered directly overhead?
Which of the following is no longer considered valid?a. the ptolemaic systemb. the copernican systemc. Kepler’s laws of planetary motiond. Newton’s law of gravity
You are lost in the northern hemisphere in the middle of nowhere on a clear night. How could you tell the direction of north by looking at the sky?
The object in the sky that apparently moves least in the course of time isa. Polarisb. Venusc. The sund. The moon
According to the physicist Richard Feynman, “Science is the culture of doubt.” Does this mean that science is an unreliable guide to the natural world?
A hypothesis isa. A new scientific ideab. A scientific idea that has been confirmed by further experiment and observationc. A scientific idea that has been discarded because it disagrees with further
What is the difference between a hypothesis and a law? Between a law and a theory?
The scientific method isa. A continuing processb. A way to arrive at ultimate truthc. A laboratory techniqued. Based on accepted laws and theories
What role does “common sense” play in the scientific method?
The brakes of a car are applied to give it an acceleration of –3 m/s2. The car comes to a stop in 5 s. What was its speed when the brakes were applied?
The acceleration of a certain moving object is constant in magnitude and direction. Must the path of the object be a straight line? If not, give an example.
Two tugboats are towing a ship. Each exerts a horizontal force of 5 tons and the angle between their towropes is 908. What net force is exerted on the ship?
A man is rowing at 8 km/h in a river 1.5 km wide in which the current is 5 km/h.(a) In what direction should he head in order to get across the river in the shortest possible time? (b) How much
Three forces, each of 10 lb, act on the same object. What is the maximum total force they can exert on the object?The minimum total force?
A snake is slithering toward you at 1.5 m/s. If you start walking when it is 5 m away, how fast must you go so that the snake will not overtake you when you have gone 100 m?
The starter of a race stands at one end of a line of runners. What is the difference in time between the arrival of the sound of his pistol at the nearest runner and at the most distant runner 10 m
Showing 1600 - 1700
of 1951
First
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20