Physics First Semester Final

Physics First Semester Final

2.1 Conceptual Questions

____1)An object is moving with constant non-zero velocity in the +x direction. The velocity versus time graph of this object is

A) / a horizontal straight line.
B) / a vertical straight line.
C) / a straight line making an angle with the time axis.
D) / a parabolic curve.

____2)Which of the following graphs represent an object at rest? (There could be more than one correct choice.)

A) / graph a
B) / graph b
C) / graph c
D) / graph d
E) / graph e

2.2 Problems

____3)A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this trip?

A) / 84 km/h
B) / 89 km/h
C) / 90 km/h
D) / 91 km/h

____4)A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip?

A) / 85 km/h
B) / 88 km/h
C) / 90 km/h
D) / 92 km/h

5)A race car circles 10 times around a circular 8.0-km track in 20 min. Using SI units

(a) what is its average speed for the ten laps?

(b) what is its average velocity for the ten laps?

6)The graph in the figure shows the position of a particle as a function of time as it travels along the x-axis.

(a) What is the average speed of the particle between t = 2.0 s and t = 4.0 s?

(b) What is the average velocity of the particle between t = 2.0 s and t = 4.0 s?

7)The graph in the figure shows the position of a particle as a function of time as it travels along the x-axis.

(a) What is the magnitude of the average velocity of the particle between t = 1.0 s and t = 4.0 s?

(b) What is the average speed of the particle between t = 1.0 s and t = 4.0 s?

____8)The graph in the figure shows the position of a particle as it travels along the x-axis. What is the magnitude of the average velocity of the particle between t = 1.0 s and t = 4.0 s?

A) / 0.25 m/s
B) / 0.50 m/s
C) / 0.67 m/s
D) / 1.0 m/s
E) / 1.3 m/s

3.1 Conceptual Questions

____9)A 10-kg rock and a 20-kg rock are thrown upward with the same initial speed v0 and experience no significant air resistance. If the 10-kg rock reaches a maximum height h, what maximum height will the 20-kg ball reach?

A) / h/4
B) / h/2
C) / h
D) / 2h
E) / 4h

____10)Two objects are thrown from the top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street? Neglect air resistance.

A) / The one thrown up is traveling faster.
B) / The one thrown down is traveling faster.
C) / They are traveling at the same speed.
D) / It is impossible to tell because the height of the building is not given.

____11)An object is moving with constant non-zero acceleration in the +x direction. The velocity versus time graph of this object is

A) / a horizontal straight line.
B) / a vertical straight line.
C) / a straight line making an angle with the time axis.
D) / a parabolic curve.

____12)A child standing on a bridge throws a rock straight down. The rock leaves the child's hand at time t = 0 s. If we take upward as the positive direction, which of the graphs shown below best represents the velocity of the stone as a function of time?

A) /
B) /
C) /
D) /
E) /

____13)A child standing on a bridge throws a rock straight down. The rock leaves the child's hand at time t = 0 s. If we take upward as the positive direction, which of the graphs shown below best represents the acceleration of the stone as a function of time?

A) / / D) /
B) / / E) /
C) /

3.2 Problems

____14)A car is traveling north at After 12 s its velocity is in the same direction. Find the magnitude and direction of the car's average acceleration.

A) / 0.30 m/s2, south
B) / 2.7 m/s2, south
C) / 0.30 m/s2, north
D) / 2.7 m/s2, north

15)A car that is initially moving at 7.50 m/s begins to accelerate forward uniformly at 0.550 m/s2.

(a) How long after beginning to accelerate does it take the car to move 3.50 km?

(b) How fast is the car moving just as it has traveled 3.50 km?

____16)A car travels at 15 m/s for 10 s. It then speeds up with a constant acceleration of 2.0 m/s2 for 15 s. At the end of this time, what is its velocity?

A) / 15 m/s
B) / 30 m/s
C) / 45 m/s
D) / 375 m/s

____17)An astronaut stands by the rim of a crater on the Moon, where the acceleration of gravity is 1.62 m/s2 and there is no air. To determine the depth of the crater, she drops a rock and measures the time it takes for it to hit the bottom. If the time is 6.3 s, what is the depth of the crater?

A) / 10 m
B) / 14 m
C) / 26 m
D) / 32 m
E) / 38 m

____18)An astronaut stands by the rim of a crater on the Moon, where the acceleration of gravity is 1.62 m/s2 and there is no air. To determine the depth of the crater, she drops a rock and measures the time it takes for it to hit the bottom. If the depth of the crater is 120 m, how long does it take for the rock to fall to the bottom of the crater?

A) / 3.04 s
B) / 12.2 s
C) / 29.3 s
D) / 32.1 s
E) / 37.5 s

4.1 Conceptual Questions

____19)If a vector pointing upward has a positive magnitude, a vector pointing downward has a negative magnitude.

A) / True
B) / False

____20)Two displacement vectors have magnitudes of 5.0 m and 7.0 m, respectively. If these two vectors are added together, the magnitude of the sum

A) / is equal to 2.0 m.
B) / could be as small as 2.0 m or as large as 12 m.
C) / is equal to 12 m.
D) / is equal to 8.6 m.

____21)The magnitude of the resultant of two vectors cannot be less than the magnitude of either of those two vectors.

A) / True
B) / False

____22)If + = and their magnitudes are given by A + B = C, then the vectors and are oriented

A) / perpendicular relative to one other.
B) / parallel to each other (in the same direction).
C) / antiparallel to each other (in opposite directions).
D) / It is impossible to know from the given information.

____23)If - = 0, then the vectors and have equal magnitudes and are directed in the same direction.

A) / True
B) / False

____24)Consider two vectors and shown in the figure. The difference - is best illustrated by

A) / choice (a)
B) / choice (b)
C) / choice (c)
D) / choice (d)

____25)For general projectile motion with no air resistance, the horizontal component of a projectile's acceleration

A) / is always zero.
B) / remains a non-zero constant.
C) / continuously increases.
D) / continuously decreases.
E) / first decreases and then increases.

____26)A player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory

A) / both the velocity and the acceleration of the soccer ball are zero.
B) / neither the ball's velocity nor its acceleration are zero.
C) / the ball's acceleration is zero but its velocity is not zero.
D) / the ball's acceleration points upward.
E) / the ball's velocity points downward.

4.2 Problems

27)A velocity vector has components 36 m/s westward and 22 m/s northward. What are the magnitude and direction of this vector?

____28)When Jeff ran up a hill at 7.0 m/s, the horizontal component of his velocity vector was 5.1 m/s. What was the vertical component of Jeff's velocity?

A) / 4.8 m/s
B) / 4.3 m/s
C) / 3.8 m/s
D) / 3.4 m/s

____29)Vector has magnitude 2 units and is directed to the north. Vector has magnitude and is directed to the south. Calculate the magnitude and direction of

A) / 7 units, north
B) / 7 units, south
C) / 3 units, north
D) / 3 units, south

____30)Vector has a magnitude of 4.0 m and points 30° south of east. Vector has a magnitude of 2.0 m and points 30° north of west. The resultant vector + is given by

A) / 10.0 m at an angle 30° south of east.
B) / 10.0 m at an angle 60° east of south.
C) / 2.0 m at an angle 60° south of east.
D) / 2.0 m at an angle 30° south of east.
E) / 1.0 m at an angle 30° east of south.

____31)Vector has a magnitude of 7.0 m and points 30° east of north. Vector has a magnitude of 5.0 m and points 30° west of south. The resultant vector + is given by

A) / 10.0 m at an angle 60° north of east.
B) / 10.0 m at an angle 30° east of north.
C) / 2.0 m at an angle 30° north of east.
D) / 2.0 m at an angle 60° north of east.
E) / 1.0 m at an angle 60° east of north

____32)Vector has a magnitude of 8.0 m and points east, vector has a magnitude of 6.0 m and points north, and vector has a magnitude of 5.0 m and points west. The resultant vector + + is given by

A) / 2.0 m at an angle 63° north of east.
B) / 2.0 m at an angle 63° east of north.
C) / 6.7 m at an angle 63° east of north.
D) / 6.7 m at an angle 63° north of east.
E) / 3.8 m at an angle 67° north of east

____33)An airplane undergoes the following displacements, all at the same altitude: First, it flies in a direction 30.0° east of north. Next, it flies due south. Finally, it flies 30.0° north of west. Use components to determine how far the airplane ends up from its starting point.

A) / 71.5 km
B) / 73.0 km
C) / 74.4 km
D) / 70.1 km
E) / 68.7 km

____34)Four vectors, , , , and , are shown in the figure. The sum of these four vectors is a vector having magnitude and direction

A) / 4.0 cm, along +x-axis.
B) / 4.0 cm, along -x-axis.
C) / 4.0 cm, along +y-axis.
D) / 4.0 cm, along -y-axis.
E) / 4.0 cm, 45° above +x-axis.

____35)The figure shows four vectors, , , , and , having magnitudes 12.0 m, 10.0 m, 8.0 m, and 4.0 m, respectively. The sum of these four vectors is

A) / 16.4 m at an angle 77.8° with respect to +x-axis.
B) / 16.4 m at an angle 12.3° with respect to +x-axis.
C) / 19.5 m at an angle 77.8° with respect to +x-axis.
D) / 19.5 m at an angle 12.3° with respect to +x-axis.
E) / 8.20 m at an angle 77.8° with respect to +x-axis.

____36)Three vectors, , , and , have the components shown in the table. What is the magnitude of the resultant of these three vectors?

x component / y component
/ 3.50 m / -4.50 m
/ 2.00 m / 0.00 m
/ -5.50 m / 2.50 m
A) / 5.50 m
B) / 13.0 m
C) / 11.1 m
D) / 7.00 m
E) / 2.00 m

____37)Three vectors, , , and , have the components shown in the table. What angle does the resultant of these three vectors make with the +x-axis?

x component / y component
/ -3.5 m / 4.5 m
/ 0.00 m / -6.5 m
/ 5.5 m / -2.5 m
A) / 24° above the +x-axis
B) / 24° below the +x-axis
C) / 66° above the +x-axis
D) / 66° below the +x-axis

____38)A ball is thrown at an original speed of 8.0 m/s at an angle of 35° above the horizontal. If there is no air resistance, what is the speed of the ball when it returns to the same horizontal level?

A) / 4.0 m/s
B) / 8.0 m/s
C) / 16 m/s
D) / 9.8 m/s

____39)A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stopwatch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the height of the cliff if air resistance is negligibly small?

A) / 22 m
B) / 43 m
C) / 77 m
D) / 91 m

____40)A fisherman casts his bait toward the river at an angle of 25° above the horizontal. As the line unravels, he notices that the bait and hook reach a maximum height of What was the initial velocity he launched the bait with? Assume that the line exerts no appreciable drag force on the bait and hook and that air resistance is negligible.

A) / 18 m/s
B) / 7.9 m/s
C) / 7.6 m/s
D) / 6.3 m/s

____41)A football kicker is attempting a field goal from out. The ball is kicked and just clears the lower bar with a time of flight of If the angle of the kick was 45°, what was the initial speed of the ball, assuming no air resistance?

A) / 21.5 m/s
B) / 19.7 m/s
C) / 2.2 m/s
D) / 39 m/s

____42)You throw a rock horizontally off a cliff with a speed of 20 m/s and no significant air resistance. After 2.0 s, the magnitude of the velocity of the rock is closest to

A) / 28 m/s
B) / 20 m/s
C) / 40 m/s
D) / 37 m/s

____43)A person throws a ball horizontally from the top of a building that is 24.0 m above the ground level. The ball lands 100 m down range from the base of the building. What was the initial velocity of the ball? Neglect air resistance and use g = 9.81 m/s2.

A) / 202 m/s
B) / 9.80 m/s
C) / 19.6 m/s
D) / 45.2 m/s
E) / 94.4°

____44)A high-speed dart is shot from ground level with a speed of 150 m/s at an angle 30° above the horizontal. What is the vertical component of its velocity after 4.0 s if air resistance is neglected?

A) / 150 m/s
B) / 36 m/s
C) / 130 m/s
D) / 75 m/s
E) / 38 m/s

____45)An athlete competing in the long jump leaves the ground with a speed of 9.14 m/s at an angle of 55° with the vertical. What is the length of the athlete's jump if air resistance is of no significance?

A) / 0.88 m
B) / 8.0 m
C) / 12 m
D) / 17 m
E) / 4.0 m

____46)A projectile is fired from ground level at an angle above the horizontal on an airless planet where g = 10.0 m/s2. The initial x and y components of its velocity are 86.6 m/s and 50.0 m/s respectively. How long after firing does it take before the projectile hits the level ground?

A) / 5.00 seconds
B) / 10.0 seconds
C) / 15.0 seconds
D) / 20.0 seconds

5.1 Conceptual Questions

____47)A box is placed on a table which rests on the floor. The box pushes on the table; the reaction force to the box's push on the table is the table's push on the floor.

A) / True
B) / False

____48)While flying horizontally in an airplane, you notice that a string dangling from the overhead luggage compartment hangs at rest at 15° away from the vertical toward the front of the plane. Using this observation, you can conclude that the airplane is

A) / moving forward.
B) / moving backward.
C) / accelerating forward.
D) / accelerating backward.
E) / not accelerating because the string is at rest.

____49)A small car and a large SUV are at a stoplight. The car has a mass equal to half that of the SUV, and the SUV can produce a maximum accelerating force equal to twice that of the car. When the light turns green, both drivers push their accelerators to the floor at the same time. Which vehicle pulls ahead of the other vehicle after a few seconds?

A) / The car pulls ahead.
B) / The SUV pulls ahead.
C) / It is a tie.

____50)An object is moving with constant non-zero velocity. Which of the following statements about it must be true?

A) / A constant force is being applied to it in the direction of motion.
B) / A constant force is being applied to it in the direction opposite of motion.
C) / A constant force is being applied to it perpendicular to the direction of motion.
D) / The net force on the object is zero.
E) / Its acceleration is in the same direction as it velocity.

____51)A push of magnitude P acts on a box of weight W as shown in the figure. The push is directed at an angle  below the horizontal, and the box remains a rest. The box rests on a horizontal surface that has some friction with the box. The normal force on the box due to the floor is equal to

A) / W.
B) / W + P.
C) / W + P cos.
D) / W + P sin .
E) / W - P sin.

____52)In the figure, what does the spring scale read? The pulleys are ideal and the strings and scale are also massless.

A) / exactly 2.0 N.
B) / exactly 1.0 N
C) / 0.50 N
D) / 0.00 N
E) / more than 19.6 N

5.2 Problems

____53)What is the mass of an object that experiences a gravitational force of 685 N near Earth's surface where g = 9.80 m/s2?

A) / 69.9 kg
B) / 68.5 kg
C) / 71.3 kg
D) / 72.7 kg

____54)If I weigh 741 N on Earth at a place where g = 9.80 m/s2 and 5320 N on the surface of another planet, what is the acceleration due to gravity on that planet?

A) / 70.4 m/s2
B) / 51.4 m/s2
C) / 61.2 m/s2
D) / 81.0 m/s2

____55)A block is on a frictionless table, on earth. The block accelerates at 5.3 m/ when a horizontal force is applied to it. The block and table are set up on the Moon where the acceleration due to gravity is 1.62 m/. A horizontal force of 5 N is now applied to the block when it is on the Moon. The acceleration imparted to the block by this force is closest to

A) / 2.7 m/.
B) / 2.4 m/.
C) / 2.9 m/.
D) / 3.2 m/.
E) / 3.4 m/.

____56)A 450-kg sports car accelerates from rest to 100 km/h in 4.80 s. What magnitude force does a 68.0 kg passenger experience during the acceleration?

A) / 394 N
B) / 82.0 N
C) / 342 N
D) / 311 N

____57)A certain aircraft has a mass of 300,000 kg. At a certain instant during its landing, its speed is 27.0 m/s. If the braking force is a constant 445,000 N, what is the speed of the airplane 10.0 s later?

A) / 10.0 m/s
B) / 12.2 m/s
C) / 14.0 m/s
D) / 18.0 m/s
E) / 20.0 m/s

____58)The figure shows an acceleration-versus-force graph for three objects pulled by wires. If the mass of object 2 is 36 kg, what are the masses of objects 1 and 3?

A) / 12 kg and 90 kg
B) / 72 kg and 18 kg
C) / 90 kg and 12 kg
D) / 12 kg and 72 kg

____59)A 50.0-kg crate is being pulled along a horizontal smooth surface. The pulling force is 10.0 N and is directed 20.0° above the horizontal. What is the magnitude of the acceleration of the crate?

A) / 0.0684 m/s2
B) / 0.188 m/s2
C) / 0.200 m/s2
D) / 0.376 m/s2
E) / 0.0728 m/s2

____60)A 10.0-kg picture is held in place by two wires, the first one hanging at 50.0° to the left of the vertical and the second one at 45.0° to the right of the vertical. What is the tension in the first wire?

A) / 69.6 N
B) / 50.8 N
C) / 98.1 N
D) / 69.4 N
E) / 23.8 N

61)Three objects are connected by weightless flexible strings as shown in the figure. The pulley has no appreciable mass or friction, and the string connected to the block on the horizontal bench pulls on it parallel to the bench surface. The coefficients of friction between the bench and the block on it are s = 0.66 and k = 0.325. You observe that this system remains at rest.

(a) Find the mass of the hanging object A.

(b) What is the magnitude of the friction force on the block on the bench?

____62)A baseball player is running to second base at 5.03 m/s. When he is 4.80 m from the plate he goes into a slide. The coefficient of kinetic friction between the player and the ground is 0.180, and the coefficient of static friction is 3.14. What is his speed when he reaches the plate?

A) / 4.47 m/s
B) / 2.89 m/s
C) / 1.96 m/s
D) / 2.56 m/s
E) / He stops before reaching the plate.

____63)A horizontal 52-N force is needed to slide a box across a flat surface at a constant velocity of 3.5 m/s. What is the coefficient of kinetic friction between the box and the floor?

A) / 0.11
B) / 0.09
C) / 0.10
D) / 0.13

____64)In a shuffleboard game, the puck slides a total of 12 m on a horizontal surface before coming to rest. If the coefficient of kinetic friction between the puck and board is 0.10, what was the initial speed of the puck?

A) / 4.8 m/s
B) / 48.5 m/s
C) / 3.8 m/s
D) / 4.3 m/s

____65)During a hockey game, a puck is given an initial speed of 10 m/s. It slides 50 m on the horizontal ice before it stops due to friction. What is the coefficient of kinetic friction between the puck and the ice?

A) / 0.090
B) / 0.10
C) / 0.11
D) / 0.12

____66)An object attached to a spring is pulled across a horizontal frictionless surface. If the force constant (spring constant) of the spring is 45 N/m and the spring is stretched by 0.88 m when the object is accelerating at what is the mass of the object?

A) / 28 kg
B) / 24 kg
C) / 31 kg
D) / 36 kg

67)A very light ideal spring having a spring constant (force constant) of 8.2 N/cm is used to lift a 2.2-kg tool with an upward acceleration of 3.25 m/s2. If the spring has negligible length when it us not stretched, how long is it while it is pulling the tool upward?

6.1 Conceptual Questions

____68)A 35-N bucket of water is lifted vertically 3.0 m and then returned to its original position. How much work did gravity do on the bucket during this process?

A) / 180 J
B) / 90 J
C) / 45 J
D) / 0 J
E) / 900 J

____69)Three cars (car L, car M, and car N) are moving with the same speed and slam on their brakes. The most massive car is car L, and the least massive is car N. If the tires of all three cars have identical coefficients of kinetic friction with the road surface, for which car is the amount of work done by friction in stopping it the greatest?

A) / The amount of work done by friction is the same for all cars.
B) / Car L
C) / Car M
D) / Car N

____70)The graphs shown show the magnitude F of the force exerted by a spring as a function of the distance x the spring has been stretched. For which one of the graphs does the spring obey Hooke's law?

A) / Graph a
B) / Graph b
C) / Graph c
D) / Graph d
E) / Graph e

____71)A person stands on the edge of a cliff. She throws three identical rocks with the same speed. Rock X is thrown vertically upward, rock Y is thrown horizontally, and rock Z is thrown vertically downward. If the ground at the base of the cliff is level, which rock hits the ground with the greatest speed if there is no air resistance?

A) / Rock X
B) / Rock Y
C) / Rock Z
D) / They all hit the ground with the same speed.

____72)A stone can slide down one of four different frictionless ramps, as shown in the figure. For which ramp will the speed of the ball be the greatest at the bottom?

A) / Ramp X
B) / Ramp Y
C) / Ramp Z
D) / The speed of the ball will be the same for all ramps.

____73)Two cyclists who weigh the same and have identical bicycles ride up the same mountain, both starting at the same time. Joe rides straight up the mountain, and Bob rides up the longer road that has a lower grade. Joe gets to the top before Bob. Ignoring friction and wind resistance, which one of the following statements is true?