PHYSICS FINAL EXAM

If you run a complete loop around an outdoor track of length 400 m in 100 s, find your (a) average velocity and (b) average speed.

(a) 0 m/s (b) 4 m/s

A 10-kg object is hanging by a very light wire in an elevator that is traveling upward. The tension in the rope is measured to be 75 N. What are the magnitude and direction of the acceleration of the elevator?

2.3 m/s2, downward

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

41 m/s at 31 degrees of west

The volume of a 10-mL test tube is equivalent to which one of the following quantities? A) 0.01 L B) 0.001 kL C) 0.1 L D) 1 × 10-6 L E) 0.001 ML

A. 0.01 L

A cat leaps to try to catch a bird. If the cat's jump was at 60° off the ground and its initial velocity was 2.74 m/s what is the highest point of its trajectory, neglecting air resistance? A) 0.29 m B) 0.58 m C) 10.96 m D) 0.19 m

A. 0.29 m

A string is wound tightly around a fixed pulley having a radius of 5.0 cm. As the string is pulled, the pulley rotates without any slipping of the string. What is the angular speed of the pulley when the string is moving at 5.0 m/s? A) 100 rad/s B) 50 rad/s C) 25 rad/s D) 20 rad/s E) 10 rad/s

A. 100 rad/s

A block is on a frictionless table, on earth. The block accelerates at 3.0 m/s2 when a 20N 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/s2. The weight of the block on the Moon is closest to A) 11 N. B) 9.5 N. C) 8.1 N. D) 6.8 N. E) 5.5 N.

A. 11 N

The components of vectors A and B are given as follows: Ax = 7.6 Bx = -5.1 Ay = -9.2 By = -6.8 What is the magnitude of the vector difference A - A ? A) 13 B) 3.5 C) 16 D) 170 E) 3.4

A. 13

A wheel accelerates from rest to 58 rad/s at a uniform rate of 58 rad/s2 Through what angle (in radians) did the wheel turn while accelerating? A) 30 rad B) 24 rad C) 60 rad D) 38 rad

A. 30 rad

The lug nuts on a car wheel require tightening to a torque of 90 N ∙ m. If a 30-cm long wrench is used, what is the magnitude of the minimum force required using the wrench? A) 300 N B) 150 N C) 30 N D) 15 N

A. 300 N

Leonardo da Vinci's Mona Lisa is 21 in. wide and 30.25 in. tall. What is the area of the painting in square centimeters? (1.00 m = 39.37 in.) A) 4,100 cm2 B) 1,600 cm2 C) 660 cm2 D) 3,300 cm2 E) 2,400 cm2

A. 4100 cm2

The figure shows a block of mass M hanging at rest. The light wire fastened to the wall is horizontal and has a tension of 38 N. The wire fastened to the ceiling is also very light, has a tension of 59N and makes an angle θ with the ceiling. Find the angle θ. *pic on phone or laptop #9, #2* A) 50° B) 40° C) 33° D) 65° E) 45°

A. 50°

Given that 1.00 in. = 2.54 cm and 1.00 yd = 36.0 in., how many meters are in 7.00 yd? A) 6.40 m B) 36.3 m C) 640 m D) 1.78 × 103 m

A. 6.40m

A torque of 12 N ∙ m is applied to a solid, uniform disk of radius 0.50 m. If the disk accelerates at 1.6 rad/s2 what is the mass of the disk (for disk, I =1/2 MR2)? A) 60 kg B) 45 kg C) 30 kg D) 15 kg

A. 60 kg

You walk 53 m to the north, then you turn 60° to your right and walk another 45m. Determine the direction of your displacement vector. Express your answer as an angle relative to east. A) 63° N of E B) 50° N of E C) 57° N of E D) 69° N of E

A. 63° N of E

A car of mass 1100 kg that is traveling at 27 m/s starts to slow down and comes to a complete stop in 578 m. What is the magnitude of the average braking force acting on the car? A) 690 N B) 550 N C) 410 N D) 340 N

A. 690 N

At a given point above Earth's surface, the acceleration due to gravity is equal to 7.8 m/s2. What is the altitude of this point above Earth's surface? (G = 6.67 × 10-11 N ∙ m2/kg2, Mearth = 5.97 × 1024 kg, Rearth = 6.38 × 106 m) A) 770 km B) 970 km C) 1500 km D) 2000 km E) 2400 km

A. 770 km

A child is riding a merry-go-round that has an instantaneous angular speed of 1.25 rad/s and an angular acceleration of 0.745 rad/s2. The child is standing 4.65 m from the center of the merry-go-round. What is the magnitude of the linear acceleration of the child? A) 8.05 m/s2 B) 7.27 m/s2 C) 2.58 m/s2 D) 3.46 m/s2 E) 4.10 m/s2

A. 8.05 m/s2

What is the angular speed, in rad/s, of a flywheel turning at 813.0 rpm? A) 85.14 rad/s B) 13.53 rad/s C) 63.84 rad/s D) 95.33 rad/s

A. 85.14 rad/s

A 1000-kg car is moving at 30 m/s around a horizontal unbanked curve whose diameter is 0.20 km. What is the magnitude of the friction force required to keep the car from sliding? A) 9000 N B) 9800 N C) 300 N D) 900 N E) 3000 N

A. 9000 N

How many significant figures are in the number 120.070? A) six B) five C) four D) three

A. six

If you stood on a planet having a mass four times that of Earth's mass, and a radius two times that of Earth's radius, you would weigh A) the same as you do on Earth. B) two times more than you do on Earth. C) two times less than you do on Earth. D) four times more than you do on Earth.

A. the same as you do on Earth

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

B. 0.188 m/s2

When a fan is turned off, its angular speed decreases from 10 rad/s to 6.3 rad/s in 5.0 s. What is the magnitude of the average angular acceleration of the fan? A) 0.86 rad/s2 B) 0.74 rad/s2 C) 0.37 rad/s2 D) 11 rad/s2 E) 1.2 rad/s2

B. 0.74 rad/s2

A 3.0-kg and a 5.0-kg box rest side-by-side on a perfectly smooth, level floor. A horizontal force of 32 N is applied to the 3.0-kg box pushing it against the 5.0-kg box, and, as a result, both boxes slide along the floor. How hard do the two boxes push against each other? A) 12 N B) 20 N C) 24 N D) 32 N E) 0 N

B. 20 N

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

B. 88 km/h

In a collision between a huge SUV and a small hybrid car, the SUV exerts a larger force on the hybrid than the hybrid exerts on the SUV. A) True B) False C) It depends on whether the collision is a head-on collision or a rear-end collision.

B. False

In the figure, block A has a mass of 3.00 kg. It rests on a smooth horizontal table and is connected by a very light horizontal string over an ideal pulley to block B, which has a mass of 2.00 kg. When block B is gently released from rest, how long does it take block B to travel 80.0 cm? *pic on phone or laptop #11, #2* A) 0.404 s B) 0.494 s C) 0.639 s D) 0.785 s E) 0.935 s

C. 0.639 s

A person is using a rope to lower a 5.0-N bucket into a well with a constant speed of 2.0 m/s. What is the magnitude of the force exerted by the rope on the bucket? A) 0.00 N B) 2.0 N C) 5.0 N D) 10 N E) 49 N

C. 10 N

If a circle has a radius of 1.109 m, what is its area expressed to the correct number of significant figures? A) 3.86 m2 B) 3.863 m2 C) 3.864 m2 D) 3.8638 m2 E) 3.86379 m2

C. 3.864 m2

A car moving at a steady 10 m/s on a level highway encounters a depression that has a circular cross-section with a radius of 30 m. The car maintains its speed as it drives through the depression. What is the normal force exerted by the seat of the car on a 60.0-kg passenger when the car is at the bottom of the depression? A) 200 N B) 390 N C) 790 N D) 490 N E) 590 N

C. 790 N

The slope of a velocity versus time graph gives A) the distance traveled. B) velocity. C) acceleration. D) displacement.

C. acceleration

A 20-g bead is attached to a light 120-cm-long string as shown in the figure. This bead moves in a horizontal circle with a constant speed of 1.5 m/s. What is the tension in the string if the angle α is measured to be 25°? *pic on phone or laptop #16, #2* A) 0.089 N B) 0.041 N C) 0.20 N D) 0.22 N E) 0.46 N

D. 0.22 N

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°

D. 45.2 m/s

The graph in the figure shows the position of a particle as it travels along the x-axis. At what value of t is the speed of the particle equal to 0 m/s? *pic is on phone or laptop, #9, #1* A) 0 s B) 1 s C) 2 s D) 3 s E) 4 s

D. 4s

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

D. 91 m

A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct? A) On the way up, its acceleration is downward and its velocity is upward, and at the highest point both its velocity and acceleration are zero. B) On the way down, both its velocity and acceleration are downward, and at the highest point both its velocity and acceleration are zero. C) Throughout the motion, the acceleration is downward, and the velocity is always in the same direction as the acceleration. D) The acceleration is downward at all points in the motion. E) The acceleration is downward at all points in the motion except that is zero at the highest point.

D. The acceleration is downward at all points in the motion.

A push of magnitude P acts on a box of weight W as shown in the figure. The push is directed at an angle θ 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 *pic on phone or laptop #6, #2* A) W. B) W + P. C) W + P cos θ. D) W + P sin θ. E) W - P sin θ.

D. W + P sin θ

A car goes around a circular curve on a horizontal road at constant speed. What is the direction of the friction force on the car due to the road? A) tangent to the curve in the forward direction B) tangent to the curve opposite to the direction of the car's motion C) perpendicular to the curve outward D) perpendicular to the curve inward E) There is no friction on the car because its speed is constant.

D. perpendicular to the curve inward

Three boxes are pulled along a horizontal frictionless floor by a constant horizontal pull P. The boxes are connected by very light horizontal strings having tensions T1 and T2 as shown in the figure. Which of the following statements about the tensions is correct? (There could be more than one correct choice.) *pic on phone or laptop #7, #2* A) T1 = P B) T2 = P C) T1 + T2 = P D) T2 > T1 E) T1 > T2

E. T1 > T2

Suppose that a car traveling to the west begins to slow down as it approaches a traffic light. Which of the following statements about its acceleration is correct? A) The acceleration is toward the east. B) Since the car is slowing down, its acceleration must be negative. C) The acceleration is zero. D) The acceleration is toward the west.

`A. The acceleration is toward the east