Questions and Answers of College Physics A Strategic Approach 2nd

In Figure 3.23, a spring-loaded “cannon” on a wheeled car fires a metal ball vertically. The car is given a push and set in motion horizontally with constant velocity. A pin is pulled with a
A student walks on a treadmill moving at 4.0 m/s and remains at the same place in the gym.(a) What is the student’s velocity relative to the gym floor?(b) What is the student’s speed relative to
What are the conditions for two vectors to add to zero?
Can a nonzero vector have a zero x-component? Explain.
A golf ball is hit on a level fairway. When it lands, its velocity vector has rotated through an angle of 90°. What was the launch angle of the golf ball? Pyo By Dyz =0 Uso Range R x max dya
Figure 3.11b shows a situation of one ball dropping from rest, and at the same time, another ball projected horizontally from the same height. The two balls hit the ground at the same time. Explain.
Is it possible for an object’s velocity to be perpendicular to the object’s acceleration? If so, describe the motion.
On Cartesian axes, the x-component of a vector is generally associated with a (a) cosine, (b) sine, (c) tangent,(d) none of the foregoing.
The equation x = xo +vxot + axt 12 2 applies (a) to all kinematic problems, (b) only if you is zero, (c) to constant accelerations, (d) to negative times.
For an object in curvilinear motion, (a) the object’s velocity components are constant, (b) the y-velocity component is necessarily greater than the x-velocity component, (c) there is an
Which one of the following cannot be a true statement about an object: (a) It has zero velocity and a nonzero acceleration; (b) it has velocity in the x-direction and acceleration in the y-direction;
Two linear vectors of magnitudes 3 and 4 are added.The magnitude of the resultant vector is (a) 1, (b) 7,(c) between 1 and
A unit vector has (a) magnitude, (b) direction, (c) neither of these, (d) both of these.
If air resistance is neglected, the motion of an object projected at an angle consists of a uniform downward acceleration combined with (a) an equal horizontal acceleration, (b) a uniform horizontal
A football is thrown on a long pass. Compared to the ball’s initial horizontal velocity component, the velocity at the highest point is (a) greater, (b) less, (c) the same.
A football is thrown on a long pass. Compared to the ball’s initial vertical velocity, the vertical component of its velocity at the highest point is (a) greater, (b) less,(c) the same.
You are traveling in a car on a straight, level road going 70 km/h. A car coming toward you appears to be traveling 130 km/h. How fast is the other car going? (a) 130 km/h,(b) 60 km/h, (c) 70 km/h,
Can the displacement of a person’s trip be zero, yet the distance involved in the trip is nonzero? How about the reverse situation? Explain.
An object traveling at a constant velocity vo experiences a constant acceleration in the same direction for a period of time t. Then an acceleration of equal magnitude is experienced in the opposite
You are told that a person has walked 750 m. What can you safely say about the person’s final position relative to the starting point?
If the displacement of an object is 300 m north, what can you say about the distance traveled by the object?
Speed is the magnitude of velocity. Is average speed the magnitude of average velocity? Explain.
The average velocity of a jogger on a straight track is computed to be +5 km/h. Is it possible for the jogger’s instantaneous velocity to be negative at any time during the jog? Explain.
A car is traveling at a constant speed of 60 mi/h on a circular track. Is the car accelerating? Explain.
Does a fast-moving object always have greater acceleration than a slower object? Give a few examples, and explain.
A classmate states that a negative acceleration always means that a moving object is decelerating. Is this statement true? Explain.
Describe the motions of the two objects that have the velocity-versus-time plots shown in Figure 2.19. Velocity 0 Time (a) (b) FIGURE 2.19 Description of motion See Conceptual
If an object’s velocity-versus-time graph is a horizontal line, what can you say about the object’s acceleration?
When a ball is thrown upward, what are its velocity and acceleration at its highest point?
Can the displacement of a person’s trip be zero, yet the distance involved in the trip be nonzero? How about the reverse situation? Explain.
A scalar quantity has (a) only magnitude, (b) only direction, (c) both magnitude and direction.
Which of the following is always true about the magnitude of the displacement: (a) it is greater than the distance traveled; (b) it is equal to the distance traveled;(c) it is less than the distance
A vector quantity has (a) only magnitude, (b) only direction, (c) both direction and magnitude.
What can be said about average speed relative to the magnitude of the average velocity?(a) greater than,(b) equal to,(c) less than,(d) both (a) and (b).
Distance is to displacement as (a) a scalar is to a scalar,(b) a vector is to a scalar, (c) a scalar is to a vector,(d) a vector is to a vector.
On a position-versus-time plot for an object that has a constant acceleration, the graph is (a) a horizontal line,(b) a non-horizontal and non-vertical straight line,(c) a vertical line, (d) a curve.
An acceleration may result from (a) an increase in speed, (b) a decrease in speed, (c) a change of direction,(d) all of the preceding.
A negative acceleration can cause(a) an increase in speed,(b) a decrease in speed,(c) either (a) or (b).
The gas pedal of an automobile is commonly referred to as the accelerator. Which of the following might also be called an accelerator: (a) the brakes, (b) the steering wheel, (c) the gear shift, or
For a constant acceleration, what changes uniformly?(a) acceleration, (b) velocity, (c) displacement,(d) distance.
Which one of the following is true for a deceleration?(a) The velocity remains constant. (b) The acceleration is negative. (c) The acceleration is in the direction opposite to the velocity. (d) The
For a constant linear acceleration, the velocity-versus time graph is (a) a horizontal line, (b) a vertical line,(c) a non-horizontal and non-vertical straight line,(d) a curved line.
For a constant linear acceleration, the position-versus time graph would be (a) a horizontal line, (b) a vertical line, (c) a non-horizontal and non-vertical straight line,(d) a curve.
Example In January 2004, a Mars Exploration Rover touched down on the surface of Mars and rolled out for exploration (▼ Figure
A couple in a sport-utility vehicle (SUV) is traveling at 90 km/h on a straight highway. The driver sees an accident in the distance and slows down to 40 km/h in
As discussed, the metric unit of mass was originally related to length, with a liter (1000 cm3) of water having a mass of 1 kg. The standard metric unit of volume is the cubic meter (m3) and this
A professor puts two equations on the board: (a) v = vo + at and(b) x = v/(2a), where x is distance in meters (m); v and vo are velocities in meters/second (m/s); a is acceleration
The world record of men’s pole vault is 6.16 m while the female record is 5.06 m. What is the difference in these heights in feet?THINKING IT THROUGH. After using the correct conversion factor,
Capillaries, the smallest blood vessels of the body, connect the arterial system with the venous system and supply our tissues with oxygen and nutrients (Figure 1.8). It is estimated that if all of
A hall bulletin board has an area of 2.5 m2. What is this area in(a) square centimeters (cm2) and (b) square inches (in2)?THINKING IT THROUGH. This problem is a conversion of area units, and we know
A grocery store has a sale on sodas. A 2-liter bottle sells for $$1.35,$ and the price of a half-gallon bottle is $$1.32.$ Which is the better buy?THINKING IT THROUGH. The answer is obtained by
The following operations are performed by finding the number that has the least number of decimal places.
A closed cylindrical container used to store material from a manufacturing process has an outside radius of 50.0 cm and a height of 1.30 m. What is the total outside surface area of the
(a) A gardener has a rectangular plot measuring 3.0 m × 4.0 m. She wishes to use half of this area to make a triangular flower bed. Of the two types of triangles shown in Figure 1.12, which should
A medical technologist draws 15 cc (cubic centimeter) of blood from a patient’s vein. Back in the lab, it is determined that this volume of blood has a mass of 16 g. Estimate the density of the
The blood volume in the human body varies with a person’s age, body size, and sex. On average, this volume is about 5.0 L. A typical value of red blood cells (erythrocytes) per volume is 5 000
How many base units are there in the SI: (a) 3, (b) 5,(c) 7, or (d) 9?
The only SI standard represented by material standard or artifact is the (a) meter, (b) kilogram, (c) second,(d) electric charge.
Which of the following is the SI base unit for mass:(a) pound, (b) gram, (c) kilogram, or (d) metric ton?
The prefix giga- means (a) 10−9, (b) 109, (c) 10−6, (d) 106.
The prefix micro- means (a) 106, (b) 10−6, (c) 103, (d) 10−3.
A new technology is concerned with objects the size of what metric prefix: (a) nano-, (b) micro-, (c) mega-, or(d) giga-?
Which of the following has the greatest volume: (a) 1 L,(b) 1 qt, (c) 2000 μL, or (d) 2000 mL?
Which of the following metric prefixes is the smallest:(a) micro-, (b) centi-, (c) nano-, or (d) milli-?
Both sides of an equation are equal in (a) numerical value, (b) units, (c) dimensions, (d) all of the preceding.
Unit analysis of an equation cannot tell you if(a) the equation is dimensionally correct,(b) the equation is physically correct,(c) the numerical value is correct,(d) both (b) and (c).
A good way to ensure proper unit conversion is (a) to use another measurement instrument, (b) always work in the same system of units, (c) use unit analysis,(d) have someone check your math.
You often see 1 kg = 2.2 lb. This expression means that(a) 1 kg is equivalent to 2.2 lb, (b) this is a true equation,(c) 1 lb = 2.2 kg, (d) none of the preceding.
You have a quantity of water and wish to express this in volume units that give the largest value. Which of the following units should be used: (a) in3, (b) mL, (c) μL, or(d) cm3?
Which of the following has the greatest number of significant figures: (a) 103.07, (b) 124.5, (c) 0.09916, or(d) 5.408 × 105?
Which of the following numbers has four significant figures: (a) 140.05, (b) 276.02, (c) 0.004 006, or(d) 0.073 004?
In a multiplication and/or division operation involving the numbers 15 437, 201.08, and 408.0 × 105, the result should have how many significant figures: (a) 3, (b) 4,(c) 5, or (d) any number?
An important step in problem solving before mathematically solving an equation is (a) checking units, (b) checking significant figures, (c) checking with a friend,(d) checking to see if the result
An important final step in problem solving before reporting an answer is (a) saving your calculations,(b) reading the problem again, (c) seeing if the answer is reasonable, (d) checking your results
In order-of-magnitude calculations, you should (a) pay close attention to significant figures, (b) work primarily in the British system, (c) get results within a factor of 100,(d) express a quantity
What replaced the original definition of the second and why? Is the replacement still used?
Give a couple of major differences between the SI and the British system.
Explain why 1 mL is equivalent to 1 cm3.
Can unit analysis tell you whether you have used the correct equation in solving a problem? Explain.
The equation for the area of a circle from two sources is given as A = πr2 and A = πd2/2. Can unit analysis tell you which is correct? Explain.
How might unit analysis help determine the units of a quantity?
Are an equation and an equivalence statement the same? Explain.
Does it make any difference whether you multiply or divide by a conversion factor? Explain.
A popular saying is “Give him an inch and he’ll take a mile.” What would be the equivalent numerical values and units in the metric system?
What is the purpose of significant figures?
Are all the significant figures reported for a measured value accurately known? Explain.
How are the number of significant figures determined for the results of calculations involving (a) multiplication,(b) division, (c) addition, and (d) subtraction?
What are the main steps in the problem-solving procedure suggested in this chapter?
When you do order-of-magnitude calculations, should you be concerned about significant figures? Explain.
When doing an order-of-magnitude calculation, how accurate can you expect the answer to be? Explain.
Is the following statement reasonable? It took 300 L of gasoline to fill the car’s tank. (Justify your answer.)
Is the following statement reasonable? A car traveling 30 km/h through a school speed zone exceeds the speed limit of 25 mi/h.
If x refers to distance, vo, and v to velocities, a to acceleration, and t to time, which of the following equations is dimensionally correct: (a) x = vote + at3,(b) v2 = vo 2 + 2at, (c) x = at +
Use SI unit analysis to show that the equation for the surface area of a sphere A = 4πr2, where A is the area and is the radius of a sphere, is dimensionally correct.
You are told that the volume of a sphere is given by V = πd3/6, where V is the volume and d is the diameter of the sphere. Is this equation dimensionally correct?
Is the equation for the area of a trapezoid, A = 1/2[a(b1 + b2)], where a is the height and b1 and b2 are the bases, dimensionally correct (▼ Figure 1.13)? -b- -b- FIGURE 1.13 The area of a
How many (a) quarts and (b) gallons are there in 10.0 L?
The sailfish is the fastest fish in the world – able to swim at a speed of 68 miles per hour (▼ Figure 1.14).(a) What is this speed expressed in m/s? (b) How long would it take the fish to travel
Using a meterstick, a student measures a length and reports it to be 0.8755 m. What is the smallest division on the meterstick scale?
The cover of your physics book measures 0.274 m long and 0.222 m wide. What is its area in square meters?

Showing 1 - 100 of 1464