Physics Test 1

N16. A 400-N steel ball is suspended by a light rope from the ceiling.. The tension in the rope is: A. 400 N B. 800 N C. zero D. 200 N E. 560 N

A. 400 N

TD17. An object is moving on a circular path of radius π meters at a constant speed of 4.0 m/s. The time required for one revolution is: A. (2/π^2) s B. (π^2/2) s C. (π/2) s D. (π^2/4) s E. (2/π) s

B. (π^2/2) s

OD20. The coordinate of an object is given as a function of time by x = 7 t - 3 t 2, where x is in meters and t is in seconds. Its average velocity over the interval from t = 0 to t = 4 s is: A. 5 m/s B. -5 m/s C. -14.5 m/s D. 11 m/s E. -11 m/s

B. -5 m/s

N32. A box sits on an inclined plane without sliding. As the angle of inclination increases, the normal force A. is directed in the direction of the gravitational force. B. decreases. C. is directed upward. D. does not change. E. increases.

B. decreases.

OD13. A baseball is thrown vertically into the air. The acceleration of the ball at its highest point is: A. zero B. g, down C. g, up D. 2g. down E. 2g, up

B. g, down

N6. The term "mass" refers to the same physical concept as: A. weight B. inertia C. force D. acceleration E. volume

B. inertia

OD19. For uniformly accelerated motion, which of the following quantities must be zero? A. the rate of change of the velocity B. the rate of change of the acceleration C. the initial displacement D. the rate of change of the displacement E. the initial velocity

B. the rate of change of the acceleration

N10. A feather and a lead ball are dropped from rest in vacuum on the Moon. The acceleration of the feather is: A. more than that of the lead ball B. the same as that of the lead ball C. less than that of the lead ball D. 9.8 m/s2 E. zero since it floats in a vacuum

B. the same as that of the lead ball

T11. A merry-go-round completes one revolution in 30 s. What is the speed of a rider located at a distance 3 m from the center of the merry go-round? A. 30 m/s B. 0.1 m/s C. 2π m/s D. 6π m/s E. 0.2π m/s

E. 0.2π m/s

N12. A crate rests on a horizontal surface and a woman pulls on it with a 10-N force. Rank the situations shown below according to the magnitude of the normal force exerted by the surface on the crate, least to greatest. 1- block right 10N 2- block up and right 10 N 3- block up 10N

E. 3, 2, 1

TD21. A boy wishes to row across a river in the shortest possible time. He can row at 2 m/s in still water and the river is flowing at 1 m/s. At what angle θ should he point the bow (front) of his boat? A. 30° B. 45° C. 60° D. 63° E. 90°

E. 90°

N24. A body moves with constant speed in a straight line. Which of the following statements must be true? A constant net force acts on the body in the direction of motion. B. A single constant force acts on the body in the direction of motion. C. No force acts on the body. D. A single constant force acts on the body in the direction opposite to the motion. E. A net force of zero acts on the body.

E. A net force of zero acts on the body.

TD8. A golfer drives her ball from the tee down the fairway in a high arcing shot. When the ball is at the highest point of its flight, A. Insufficient information is given to answer correctly. B. its velocity is nonzero but its acceleration is zero. C. its velocity is zero but its acceleration is nonzero. D. its velocity and acceleration are both zero. E. its velocity and acceleration are both nonzero.

E. its velocity and acceleration are both nonzero.

N14. A car travels east at constant velocity. The net force on the car is: A. east B. west C. up D. down E. zero

E. zero

OD6. A car starts from Hither, goes 50 km in a straight line to Yon, immediately turns around, and returns to Hither. The time for this round trip is 2 hours. The magnitude of the average velocity of the car for this round trip is: A. 0 B. 50 km/hr C. 100 km/hr D. 200 km/hr E. cannot be calculated without knowing the acceleration

A. 0

TD20. A boat is traveling upstream at 14 mph with respect to a river that is flowing at 6 mph (with respect to the ground). A man runs directly across the boat, from one side to the other, at 6 mph (with respect to the boat). The speed of the man with respect to the ground is: A. 10 mph B. 14 mph C. 18.5 mph D. 21 mph E. 26 mph

A. 10 mph

N18. A car moves horizontally with a constant acceleration of 3 m/s 2. A ball is suspended by a string from the ceiling of the car; the ball does not swing, being at rest with respect to the car. What angle does the string make with the vertical? A. 17° B. 35° C. 52° D. 73° E. Cannot be found without knowing the length of the string

A. 17°

TD22. A girl wishes to swim across a river to a point directly opposite as shown. She can swim at 2 m/s in still water and the river is flowing at 1 m/s. At what angle θ with respect to the line joining the starting and finishing points should she swim? A. 30° B. 45° C. 60° D. 63° E. 90°

A. 30°

N2. Which of the following quantities is NOT a vector? A. Mass B. Displacement C. Weight D. Acceleration E. Force

A. Mass

OD11. A ball is in free fall. Its acceleration is: A. downward during both ascent and descent B. upward during ascent and downward during descent C. upward during both ascent and descent D. downward at all times except at the very top, when it is zero E. downward during ascent and upward during descent

A. downward during both ascent and descent

N29. The weight of an object is A. the result of the gravitational force acting on the object. B. the reading on a spring scale attached to the object. C. the same as the mass of the object. D. the mass of the object multiplied by the acceleration due to gravity at sea level, regardless of where the object is located. E. the quantity of matter in the object.

A. the result of the gravitational force acting on the object.

OD17. If the position of an object is plotted vertically on a graph and the time is plotted horizontally, the instantaneous velocity at a particular time is A. the slope of the tangent to the curve at that time. B. the total length of the curve. C. the height of the curve at that time. D. the area under the curve from zero to that time. E. impossible to determine from this type of plot.

A. the slope of the tangent to the curve at that time.

OD8. The coordinate of a particle in meters is given by x( t) = 16 t - 3.0 t 3, where the time t is in seconds. The particle is momentarily at rest at t = A. 0.75 s B. 1.3 s C. 5.3 s D. 7.3 s E. 9.3 s

B. 1.3 s

N26. A force accelerates a body of mass M. A second body requires twice as much force to produce the same acceleration. What is the mass of the second body? A. M B. 2M C. M/2 D. M/4 E. 4M

B. 2M

TD16. A boy on the edge of a vertical cliff 20 m high throws a stone horizontally outwards with a speed of 20 m/s. It strikes the ground at what horizontal distance from the foot of the cliff? Use g = 10 m/s 2 A. 10 m B. 40 m C. 50 m D. 50 squareroot 5 m E. none of these

B. 40 m

N34. Three blocks are connected by massless cords and rest on a frictionless horizontal surface. The blocks are pulled to the right. Mass m 1 = 2 m 2 = 3 m 3, with m 1 on the left and m 3 on the right. If the pulling force is equal to 90 N, then the tension in the cord between m 1 and m 2 is m1-m2-m3- F-> A. 100 N B. 49 N C. 15 N D. 85 N E. 44 N

B. 49 N

OD7. A car starts from Hither, goes 50 km in a straight line to Yon, immediately turns around, and returns to Hither. The time for this round trip is 2 hours. The average speed of the car for this round trip is: A. 0 B. 50 km/h C. 100 km/h D. 200 km/h E. cannot be calculated without knowing the acceleration

B. 50 km/h

OD2. You drive for 30 min for 30 km East and then another 30 min for 40 km North. Your average speed for the entire trip is A. 80 km/h. B. 70 km/h. C. 50 km/h. D. 60 km/h. E. 40 km/h.

B. 70 km/h.

N22. Three blocks (A,B,C), each having mass M, are connected by strings as shown. Block C is pulled to the right by a force F that causes the entire system to accelerate. Neglecting friction, the net force acting on block B is: A-B-C- F-> A. zero B. F/3 C. F/2 D. 2 F/3 E. F

B. F/3

OD9. A drag racing car starts from rest at t = 0 and moves along a straight line with velocity given by v = bt 2, where b is a constant. The expression for the distance traveled by this car from its position at t = 0 is: A. bt^3 B. bt^3 / 3 C. 4bt^2 D. 3bt^2 E. bt^(3/2)

B. bt^3 / 3

OD15. An object is shot vertically upward. While it is rising: A. its velocity and acceleration are both upward B. its velocity is upward and its acceleration is downward C. its velocity and acceleration are both downward D. its velocity is downward and its acceleration is upward E. its velocity and acceleration are both decreasing

B. its velocity is upward and its acceleration is downward

OD4. The average speed of a moving object during a given interval of time is always: A. the magnitude of its average velocity over the interval B. the distance covered during the time interval divided by the time interval C. one-half its speed at the end of the interval D. its acceleration multiplied by the time interval E. one-half its acceleration multiplied by the time interval.

B. the distance covered during the time interval divided by the time interval

N20. A book rests on a table, exerting a downward force on the table. The reaction to this force is: A. the force of the Earth on the book B. the force of the table on the book C. the force of the Earth on the table D. the force of the book on the Earth E. the inertia of the book

B. the force of the table on the book

N19. The "reaction" force does not cancel the "action" force because: A. the action force is greater than the reaction force B. they are on different bodies C. they are in the same direction D. the reaction force exists only after the action force is removed E. the reaction force is greater than the action force

B. they are on different bodies

N8. Mass differs from weight in that: A. all objects have weight but some lack mass B. weight is a force and mass is not C. the mass of an object is always more than its weight D. mass can only be expressed in the metric system E. there is no difference

B. weight is a force and mass is not

TD3. A pilot wants the heading of an airplane to be 37º east of north. The wind is from the east at 37 km/h. The airplane has a speed relative to the air of 370 km/h. Approximately what heading should the pilot maintain? ( Hint: Sketch the problem graphically and select the best answer from the list given.) (Due north is 0º and due east is 90º ) A.122º B.42º C.32º D.318º E.4.6º

B.42º

N4. A force of 1 N is: A. 1 kg/s B. 1kg ⋅ m/s C. 1kg ⋅ m/s^2 D. 1kg ⋅ m^2/s E. 1kg ⋅ m^2/s2

C. 1kg ⋅ m/s^2

TD4. A projectile is fired with an initial speed of 1000 m/s at an angle of 37º above the horizontal. If air resistance is neglected, the horizontal component of the projectile's velocity after 20 s is approximately A. 600 m/s B. 40 m/s C. 800 m/s D. 640 m/s E. 160 m/s

C. 800 m/s

N25. A force accelerates a body of mass M. The same force applied to a second body produces three times the acceleration. What is the mass of the second body? A. M/9 B. 3M C. M/3 D. M E. 9M

C. M/3

OD10. ach of four particles move along an x axis. Their coordinates (in meters) as functions of time (in seconds) are given by particle 1: x( t) = 3.5 - 2.7 t 3 particle 2: x( t) = 3.5 + 2.7 t 3 particle 3: x( t) = 3.5 + 2.7 t 2 particle 4: x( t) = 3.5 - 3.4 t - 2.7 t 2 Which of these particles have constant acceleration? A. All four B. None of them C. Only 3 and 4 D. Only 2 and 3 E. Only 1 and 2

C. Only 3 and 4

TD15. A bomber flying in level flight with constant velocity releases a bomb before it is over the target. Neglecting air resistance, which one of the following is NOT true? A. The bomber is over the target when the bomb strikes B. The acceleration of the bomb is constant C. The horizontal velocity of the plane equals the vertical velocity of the bomb when it hits the target D. The bomb travels in a curved path E. The time of flight of the bomb is independent of the horizontal speed of the plane

C. The horizontal velocity of the plane equals the vertical velocity of the bomb when it hits the target

N15. An object rests on a horizontal frictionless surface. A horizontal force of magnitude F is applied. This force produces an acceleration: A. only if F is larger than the weight of the object B. only while the object suddenly changes from rest to motion C. always D. only if the inertia of the object decreases E. only if F is increasing

C. always

TD19. A stone is tied to a string and whirled at constant speed in a horizontal circle. The speed is then doubled without changing the length of the string. Afterward the magnitude of the acceleration of the stone is: A. the same B. twice as great C. four times as great D. half as great E. one-fourth as great

C. four times as great

N9. The mass of a body: A. is slightly different at different places on the Earth B. is a vector C. is independent of the acceleration due to gravity D. is the same for all bodies of the same volume E. can be measured most accurately on a spring scale

C. is independent of the acceleration due to gravity

TD18. A particle moves at constant speed in a circular path. The instantaneous velocity and instantaneous acceleration vectors are: A. both tangent to the circular path B. both perpendicular to the circular path C. perpendicular to each other D. opposite to each other E. none of the above

C. perpendicular to each other

N7. The inertia of a body tends to cause the body to: A. speed up B. slow down C. resist any change in its motion D. fall toward the Earth E. decelerate due to friction

C. resist any change in its motion

N17. A 1-N pendulum bob is held at an angle θ from the vertical by a 2-N horizontal force F as shown. The tension in the string supporting the pendulum bob (in newtons) is: A. cos θ B. 2/cos θ C. squareroot 5 D. 1 E. none of these

C. squareroot 5

TD14. A bullet shot horizontally from a gun: A. strikes the ground much later than one dropped vertically from the same point at the same instant B. never strikes the ground C. strikes the ground at approximately the same time as one dropped vertically from the same point at the same instant D. travels in a straight line E. strikes the ground much sooner than one dropped from the same point at the same instant

C. strikes the ground at approximately the same time as one dropped vertically from the same point at the same instant

OD18. If an object is moving at uniform speed in a straight line, its instantaneous velocity halfway through any time interval is A. half of its average velocity. B. twice its average velocity. C. the same as its average velocity. D. greater than its average velocity. E. less than its average velocity.

C. the same as its average velocity.

OD14. A freely falling body has a constant acceleration of 9.8 m/s 2. This means that: A. the body falls 9.8 m during each second B. the body falls 9.8 m during the first second C. the speed of the body increases by 9.8 m/s during each second D. the acceleration of the body increases by 9.8 m/s2 during each second E. the acceleration of the body decreases by 9.8 m/s2 during each second

C. the speed of the body increases by 9.8 m/s during each second

TD9. You shoot an arrow in a high arc toward a target located some distance away. At the highest point in its flight, the arrow's A. Insufficient information is given to answer correctly. B. velocity is nonzero but its acceleration is zero. C. velocity and acceleration are both nonzero. D. velocity and acceleration are both zero. E. velocity is zero but its acceleration is nonzero.

C. velocity and acceleration are both nonzero.

TD12. A merry-go-round completes one revolution in 40 s. What is the centripetal acceleration of a rider located at a distance 2 m from the center of the merry go-round? A. π2/100 m/s2 B. 1/4 m/s2 C. π2/200 m/s2 D. π2 m/s2 E. 1/4 π m/s2

C. π2/200 m/s2

R6. The position of a particle is given as x(t) = 12t - 3.0t2, where x is in meters and t is in seconds. It is momentarily at rest when t = A.0.0 s B.1.0 s C.2.0 s D.3.0 s E.4.0 s

C.2.0 s dx/dt = 12 - 3.0t = 0 t = 2s

N33. Two masses m 1 and m 2 (with m 2 > m 1) are connected by a massless rope hung over a frictionless light pulley. If the masses are released then the acceleration of m 2 in the downward direction is given by A. g B. (m1 + m2) × g/(m2 - m1) C. (m2 - m1) × g/(m1 - m2) D. (m2 - m1) × g/(m1 + m2) E. m2 × g/(m1 + m2)

D. (m2 - m1) × g/(m1 + m2)

TD1. The position vector of an object is given by r1 = 2i + 3J and 4 s later, its position vector is r2 = -2i + 7j. The units are in m. The change in the position vector delta r , in m, is

D. -4i + 4j

OD1. A particle moves from x 1 = 30 cm to x 2 = - 40 cm. The displacement of this particle is A. 40 cm B. 70 cm C. - 40 cm D. -70 cm E. 30 cm

D. -70 cm

N11. The block shown moves with constant velocity on a horizontal surface. Two of the forces on it are shown. A frictional force exerted by the surface is the only other horizontal force on the block. The frictional force is: <- 3N block 5N -> A. slightly less than 2 N, leftward B. 2 N, rightward C. 0 D. 2 N, leftward E. slightly more than 2 N, leftward

D. 2 N, leftward

OD5. A car travels 40 kilometers at an average speed of 80 km/h and then travels 40 kilometers at an average speed of 40 km/h. The average speed of the car for this 80 km trip is: A. 40 km/h B. 45 km/h C. 48 km/h D. 53 km/h E. 80 km/h

D. 53 km/h

N27. An object is moving to the right at a constant speed. Which one of the following statements must be correct? A. No forces are acting on the object. B. Just one force is acting on the object, and it is acting downward. C. The net force acting on the object is to the right. D. No net force is acting on the object. E. A larger number of forces are acting on the object to the right than to the left.

D. No net force is acting on the object.

TD7. A stone with a mass m is dropped from an airplane that has a horizontal velocity v at a height h above a lake. If air resistance is neglected, the horizontal distance R from the point on the lake directly below the point of release to the point where the stone strikes the water is given by which formula? A. R = v(2h/g)2 B. R = (1/2)gt2 C. R = 2mv squareroot (2h/g) D. R = v squareroot (2h/g) E. None of these is correct.

D. R = v squareroot (2h/g)

N30. A body is sent out in space. Which of the following statements is true of this body as it moves away from Earth? A. The body's mass decreases, and its weight increases. B. The body's mass decreases, and its weight remains constant. C. The body's mass and weight remain equal. D. The body's mass remains constant, and its weight decreases. E. The body's mass and weight decrease.

D. The body's mass remains constant, and its weight decreases.

N28. Which of the following statements is true? A. The unit of mass in the U.S. customary system is the newton. B. Mass is a vector quantity. C. The mass of a body is inversely proportional to the resultant force acting on it. D. The mass of a body is a quantitative measure of its inertia. E. The mass of a body is directly proportional to the acceleration it is experiencing.

D. The mass of a body is a quantitative measure of its inertia.

TD2. A river is 0.76 km wide. The banks are straight and parallel. The current is 5.0 km/h and is parallel to the banks. A boat has a maximum speed of 3 km/h in still water. The pilot of the boat wishes to travel on a straight line from A to B, where AB is perpendicular to the banks. The pilot should A. head directly across the river. B. head 68º upstream from the line AB. C. head 22º upstream from the line AB. D. give up. The trip from A to B is not possible with this boat. E. do none of these.

D. give up. The trip from A to B is not possible with this boat.

TD10. If you ignore air resistance in projectile motion, the ________ of the projectile remains constant. A. range B. velocity vector C. vertical component of the velocity vector D. horizontal component of the velocity vector E. speed

D. horizontal component of the velocity vector

N13. A heavy wooden block is dragged by a force ¢ along a rough steel plate, as shown below for two cases. The magnitude of the applied force ¢ is the same for both cases. The normal force in (ii), as compared with the normal force in (i) is: A. less B. the same C. greater D. less or greater, depending on the magnitude of the applied force ¢. E. less for some angles of the incline and greater for others

D. less

OD16. The displacement of an object during any time interval is always ________ the distance it travels during that same time interval. A. much greater than B. greater than or equal to C. equal to D. less than or equal to E. greater than

D. less than or equal to

N5. Acceleration is always in the direction: A. of the displacement B. of the initial velocity C. of the final velocity D. of the net force E. opposite to the frictional force

D. of the net force

TD13. A stone thrown from the top of a tall building follows a path that is: A. circular B. made of two straight line segments C. hyperbolic D. parabolic E. a straight line

D. parabolic

OD12. A ball is in free fall. Upward is taken to be the positive direction. The displacement of the ball is: A. positive during both ascent and descent B. negative during both ascent and descent C. negative during ascent and positive during descent D. positive during ascent and negative during descent E. none of the above

D. positive during ascent and negative during descent

N3. A newton is the force: A. of gravity on a 1 kg body B. of gravity on a 1 g body C. that gives a l g body an acceleration of 1 cm/s^2 D. that gives a 1 kg body an acceleration of 1 m/s^2 E. that gives a 1 kg body an acceleration of 9.8 m/s^2

D. that gives a 1 kg body an acceleration of 1 m/s^2

N21. Three books (X, Y, and Z) rest on a table. The weight of each book is indicated. The net force acting on book Y is: X- 4N Y- 5N Z- 10N A. 4 N down B. 5 N up C. 9 N down D. zero E. none of these

D. zero

R4. A vector of magnitude 12 is added to a vector of magnitude 7. The magnitude of the sum can be: A.0 B.4 C.24 D.15 Any of these values are possible

D.15

R2. An object with a mass of 2.0 kg is dropped from a certain location and it takes 2.0 s to hit the ground. Then an object with a mass of 4.0 kg is dropped from the same point. How long does it take to hit the ground? (ignore air resistance)? A.0.5 s B.1.0 s C.1.5 s D.2.0 s E.4.0 s

D.2.0 s

R3. Mass is a quantitative measure of A.grams B.weight C.Force D.Inertia E.volume

D.Inertia

R1. A body moves at a constant speed in a straight line. Which of the following must be true? A.No forces act on the body B.A constant force is applied to the body C.The body is on a frictionless surface D.No unbalanced force acts on the body

D.No unbalanced force acts on the body

N23. When Newton's first law of motion is mentioned, you should immediately think of A. gravitational forces. B. Fnet = ma C. action-and-reaction forces. D. centripetal acceleration. E. inertia.

E. inertia.

OD3. The displacement of an object for a round trip between two locations A. is always less than zero. B. can have any value. C. can be greater than or less than but not equal to zero. D. is always greater than zero. E. is zero.

E. is zero.

N1. A physical quantity that is sometimes described as the measure of the resistance of a body to a change in motion is A. friction B. acceleration C. force D. weight E. mass

E. mass

N31. The word "normal," as it applies to forces, means A. straight up, in the direction opposite to the force of gravity. B. usual. C. mean. D. average. E. perpendicular. Question 32

E. perpendicular.

TD6. A baseball is thrown with a velocity at an angle θ with the horizontal. The horizontal component of its velocity in the absence of air resistance is A. v2 - 2gx B. v cos θ - gt C. v2 + 2gx D. v sin θ - gt E. v cos θ

E. v cos θ

R5. 1.Two metal balls are the same size but one weighs twice as much as the other. The balls roll off the edge of a horizontal table with the same speed. In this situation: A.the heavier ball hits the floor at about half the horizontal distance from the base of the table than does the lighter ball. B.the lighter ball hits the floor at about half the horizontal distance from the base of the table than does the heavier ball. C.the heavier ball hits the floor considerably closer to the base of the table than the lighter ball, but not necessarily half the distance. D.the lighter ball hits the floor considerably closer to the base of the table than the heavier ball, but not necessarily half the distance. E.both balls hit the floor at approximately the same horizontal distance from the base of the table

E.both balls hit the floor at approximately the same horizontal distance from the base of the table

TD5. Which of the following statements is not true of a projectile moving near the surface of the earth against negligible air resistance? A. The horizontal displacement is directly proportional to the time of flight. B. The vertical velocity at any given time is independent of the angle of projection. C. The vertical acceleration is constant. D. The horizontal velocity is constant. E. The horizontal acceleration is constant.

not E, C