PHYSC Final Exam
A 80 kg hiker climbs a mountain in 8.0 hours. If the climber's vertical elevation increases 3.6 km, what is the average power of the process needed for the increase in gravitational energy? A: 105 W B: 98 W C: 55 W D: 435 W E: 20 W
Answer 98 W
A large block is attached to a spring scale which measures a weight of 250 N. The block is then completely submerged in water, which has a density of 1000 kg/m3. The spring scale then reads 200 N. What is the volume of the block? A: .005 m3 B: .02 m3 C: .025 m3 D: .05 m3 E: .01 m3
Answer A: .005 m3
A 2.00 m long horizontal uniform beam of mass 20.0 kg is supported by a wire as shown in the figure. The wire makes an angle of 20.0 degrees with the beam. Attached to the beam, 1.40 m from the wall, is a ball with a mass of 40 kg. What is the tension in the wire? A: 1,090 N B: 2,100 N C: 2,680 N D: 1,000 N E: 2,250 N
Answer A: 1,090 N
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 kg passenger when the car is at the bottom of the depression? A:790 N B: 390 N C: 490 N D: 590 N E: 200 N
Answer A: 790 N
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: 8.00 m B: 0.88 m C: 17.00 m D: 12.00 m E: 4.00 m
Answer A: 8.00 m
A 1200 kg car is traveling at 3.00 m/s and strikes a wall. The car bounces off the wall with a velocity of 4.00 m/s. If the contact with the wall by the car lasts for 0.10 seconds, then the average force on the car is: A: 84,000 N B: 46,000 N C: 55,000 N D: 63,000 N E: 75,000 N
Answer A: 84,000 N
A pulley with radius 0.2 m and mass M = 1.5 kg is attached to a falling bucket with mass m = 1.5 kg. What will be the linear acceleration of the falling bucket after it is released? Model the pulley as a uniform disk. A: 3.2 m/s2 B: 9.8 m/s2 C: 4.9 m/s2 D: 6.5 m/s2 E:7.4 m/s2
Answer D: 6.5 m/s2
The weight of a 10.00 kg object on the surface of the Moon is: (G = 6.67 x 10-11 N · m2/kg2, R of the Moon is 1.74 x 106 m, mass of the Moon is 7.35 x 1022 kg): A: 16.2 N B: 98 N C: 9.80 N D: 75.0 N E: 5.40 N
Answer A : 16.2 N
A tractor (T) is pulling a trailer (M) with a constant velocity (there is no friction). If the velocity is 20 m/s and M = 200 kg and T = 500 kg, then the force on the trailer due to the tractor is: A: 0. B: 200 N backward. C: 600 N forward. D: 450 N backward. E: 35 N forward
Answer A: 0
Two carts are involved in an inelastic collision. Cart A with a mass 1.0 kg hits cart B with a mass 0.5 kg. The two carts stick together after the collision and continue to move along together. Cart A has an initial velocity of 2.0 m/s and cart B is initially at rest. What is the final velocity of the two-cart system? A: 1.3 m/s B: 0.7 m/s C: 1.7 m/s D: 2.0 m/s E: 1.0 m/s
Answer A: 1.3 m/s
Two small balls, A and B, attract each other gravitationally with a force of magnitude F. If we now double both masses and also double the distance of separation between the balls, what will be the magnitude of the attractive force on each one? A: F B: 8F C: 4F D: 16F E: F / 4
Answer A: F
A 10 kg piece of aluminum sits at the bottom of a lake, right next to a 10 kg piece of lead, which is much denser than aluminum. Which one has the greater buoyant force on it? A: The aluminum. B: The lead. C: Both have the same bouyant force. D: It cannot be determined without knowing their volumes.
Answer A: The aluminum
In any collision: A: Total momentum is conserved. B: Total momentum is not conserved but total kinetic energy is conserved. C: Total momentum is not conserved. D: Total kinetic energy is conserved. E: Total momentum and total kinetic energy are conserved and the masses are equal.
Answer A: Total momentum is conserved
A pilot drops a package from a plane flying horizontally at a constant speed. Neglecting air resistance, when the package hits the ground the horizontal location of the plane will... A be directly over the package. B: depend on the speed of the plane when the package was released. C: be behind the package. D: be in front of the package. E: None of the above.
Answer A: be directly over the package.
What buoyant force does a 0.50 kg solid gold crown experience when it is immersed in water? The density of gold is 19.3 x 103 kg/m3 and that of water is 1000 kg/m3. A: 4.9 x 103 N B: 0.25 N C: 1.9 x 102 N D: 2.5 x 102 N E: 3.04 x 10-4 N
Answer B: 0.25 N
An ice dancer with her arms stretched out starts into a spin with an angular velocity of 1.00 rad/s. Her moment of inertia with her arms stretched out is 2.48 kg•m2. What is the increase in her rotational kinetic energy when she pulls in her arms to make her moment of inertia 1.40 kg•m2? A: 0.750 J B: 0.957 J C: 0.870 J D: 0.690 J E: 0.902 J
Answer B: 0.957 J
A 3.00 kg hollow sphere of radius 5.00 cm starts from rest and rolls without slipping down a 15.0 degree incline. If the length of the incline is 100 cm, then the velocity of the center of mass of the hollow sphere at the bottom of the incline is: A: 3.02 m/s B: 1.75 m/s C: 2.02 m/s D: 2.59 m/s E: 2.37 m/s
Answer B: 1.75 m/s
A 30.0 cm wrench is used to generate a torque at a bolt. A force of 50.0 N is applied at the end of the wrench at an angle of 70.0 degrees. The torque generated at the bolt is: A: 26.2 N•m B: 14.1 N•m C: 10.4 N•m D: 21.5 N•m E: 19.7 N•m
Answer B: 14.1 N*m
A rock falls off a cliff at height 50 m above ground. Ignoring air resistance, how long does it take for the rock to attain a speed of 110 km/h? A: 1.8 s B: 3.1 s C: 2.8 s D: 2.1 s E: The rock will hit the ground before reaching 110 km/h.
Answer B: 3.1s
A submarine is at a depth of 500 m under the water. The force on a circular hatch of 1.00 m in diameter due to the seawater (density = 1,025 kg/m3) pressure from outside the submarine is: A: 4.94 x 106 N B: 3.95 x 106 N C: 5.50 x 106 N D: 6.34 x 106 N E: 2.45 x 106 N
Answer B: 3.95 x 106 N
A driver in a 2000- kg classic car traveling at 90 km/h slams on the brakes and skids to a stop. If the coefficient of friction between the tires and the level road is 0.80, how long will the skid marks be? A: 34 m B: 40 m C: 46 m D: 19 m E: 32 m
Answer B: 40m
Two masses are connected by a string which passes over a pulley with negligible mass and friction. One mass hangs vertically and one mass slides on a 30.0 degree frictionless incline. The vertically hanging mass is 6.00 kg and the mass on the incline is 4.00 kg. The acceleration of the 4.00 kg mass is: A: 1.98 m/s2 B: 7.84 m/s2 C: 6.86 m/s2 D: 3.92 m/s2 E: 5.75 m/s2
Answer B: 7.84 m/s2
A roller coaster has a vertical loop with radius 9.8 m. What is the minimum speed at which the car must be moving at the top so that the passengers do not lose contact with the seats? A: 19.6 m/s B: 9.8 m/s C: 29.4 m/s D: 0.98 m/s E: 4.9 m/s
Answer B: 9.8 m/s
A ball's initial position is < 10, 4, -6 > m, and the ball's velocity is < 3, -2, 4 > m/s. What is the position of the ball 3 seconds later? Assume that the ball's velocity does not change significantly in this short time interval. A: < 1, 10, -18 > m B: < 19, -2, 6 > m C: < 13, 2, -2 > m D: < 9, -6, 12 > m E: None of the above
Answer B: <19, -2, 6> m
A person sits on a freely spinning lab stool that has no friction in its axle. The person is spun around by a friend. When this person extends her arms while spinning: A: Her moment of inertia increases and her angular speed remains the same. B: Her moment of inertia increases and her angular speed decreases. C: Her moment of inertia decreases and her angular speed increases. D Her moment of inertia decreases and her angular speed decreases. E:Her moment of inertia increases and her angular speed increases.
Answer B: Her moment of inertia increases and her angular speed decreases.
A ball is thrown straight up into the air. At the highest point: A:neither the acceleration nor the velocity are zero. B: the A ball is thrown straight up into the air. C:the acceleration vector is pointing upward. D:the acceleration is zero but the velocity is not zero. E: both the velocity and the acceleration are zero.
Answer B: the A ball is thrown straight up into the air.
A 4.00 kg mass is moving in a circular path with a constant angular velocity of 5.00 rad/s and with a tangential velocity of 5.00 m/s. The centripetal force on the mass is: A: 125 N B: 200 N C: 100 N D: 169 N E: 90.0 N
Answer C: 100N
A cart is released from rest on a uniform ramp, shown below. The total distance of the incline from start to finish that the cart travels is 200 m. The final velocity of the cart at the bottom of the incline is 45 m/s. What is the velocity of the cart at the halfway point? A: 28 m/s B: 18 m/s C: 32 m/s D: 30 m/s E: 42 m/s
Answer C: 32m/s
The pressure in a bottle is 40 PSI at room temperature (20° C). The bottle temperature is slowly increased to 90° C. What is the pressure in the bottle at 90° C? A: 40 PSI B: 180 PSI C: 50 PSI D: 55 PSI E: 32 PSI
Answer C: 50 PSI
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 59 N, and makes an angle θ with the ceiling. Find the angle θ. A: 45° B: 65° C: 50° D: 33° E: 40°
Answer C: 50°
A merry-go-around of radius 2 m and moment of inertia 100 kg m2 is initially at rest. A kid of mass 40 kg is running tangentially to the perimeter of the merry-go-around at a speed 2 m/s, and jumps on. What is the rotational velocity of the merry-go-around with the kid on it? A: 1.30 rad/s B: 0.31 rad/s C: 1.60 rad/s D: 0.62 rad/s E: 0.80 rad/s
Answer D: 0.62 rad/s
A CD has a diameter of 12.0 cm. If the CD is rotating at a constant angular speed of 200 revolutions per minute, then the tangential velocity of a point on the circumference is: A: 1.62 m/s B: 1.32 m/s C: 1.06 m/s D: 1.26 m/s E: 1.39 m/s
Answer D: 1.25 m/s
A block is on a frictionless table. The block accelerates at 3.0 m/s2 when a 20 N 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: 5.5 N B: 9.5 N C: 6.8 N D: 11 N E: 8.1 N
Answer D: 11N
An ideal gas takes up 600 cm3 of volume at a temperature of 25° C. At what temperature will this same gas occupy 1150 cm3 if the pressure is held constant? A: 313° C B: 248° C C: 571° C D: 298° C E: 48° C
Answer D: 298 C
A person who weighs 100 kg hops onto a rowing boat. The boat sinks an additional 2 cm deeper into the water. What is the cross-sectional area of the boat? Assume the seawater density is 1000 kg/m3. A 5.5 m2 B: 10 m2 C: 3.0 m2 D: 5.0 m2 E: 2.0 m2
Answer D: 5.0 m2
A 1000 kg car is moving at 30 m/s around a horizontal unbanked curve whose radius is 0.10 km. What is the magnitude of the friction force required to keep the car from sliding? A: 900 N B: 9800 N C: 3000 N D: 9000 N E: 300 N
Answer D: 9000N
Earth mass is M=5.97 × 1024 kg and its radius is R=6370 km. The International Space Station (ISS) is orbiting the Earth at an altitude of 410 km. How long does it take for the ISS to circle the Earth once? A: 740 min B: 260 min C: 1440 min D: 93 min E: 980 min
Answer D: 93 min
A 45.0 kg person steps on a scale in an elevator. The scale reads 460 N. What is the magnitude of the acceleration of the elevator? A: 9.81 m/s2 B: 4.91 m/s2 C: 46.9 m/s2 D: 0.206 m/s2 E: 0.422 m/s2
Answer E: 0.422 m/s2
A flywheel has a rotational inertia of I = 1000 kg m2. It is initially rotating at 1000 rpm. You want to stop the wheel in 60 sec. What resistive torque must you apply? A: 278 N•m B: 105,000 N•m C: 1.75 N•m D: 500 N•m E: 1750 N•m
Answer E: 1750 N*m
How many moles are there in 2.00 kg of copper? The atomic weight of copper is 63.5 g/mol and its density is 8.90 g/cm3. A: 13.5 B: 53.1 C: 51.3 D: 15.3 E: 31.5
Answer E: 31.5
