PHYS-91 Science Bowl Exam Questions and Answers for Physics 2024.

PHYS-91 Science Bowl Exam Questions and Answers for Physics 2024. Science Bowl PHYSICS Physics - 1 PHYS-91; Multiple Choice: For the hydrogen atom, which series describes electron transitions to the N=1 orbit, the lowest energy electron orbit? Is it the: w) Lyman series x) Balmer series y) Paschen series z) Pfund series ANSWER: W -- LYMAN SERIES PHYS-91; Multiple Choice: Electric current may be expressed in which one of the following units? w) coulombs/volt x) joules/coulomb y) coulombs/second z) ohms/second ANSWER: Y -- COULOMBS/SECOND PHYS-91; Short Answer: In the SI system of measure, what is the unit of capacitance? ANSWER: FARAD PHYS-91; Multiple Choice: A Newton is equal to which of the following? w) kilogram-meter per second x) meter per second squared y) kilogram-meter per second squared z) kilogram per meter-second ANSWER: Y -- KILOGRAM-METER PER SECOND SQUARED PHYS-91; Multiple Choice: For an object moving in uniform circular motion, the direction of the instantaneous acceleration vector is: w) tangent to the path of motion x) equal to zero y) directed radially outward z) directed radially inward ANSWER: Z -- DIRECTED RADIALLY INWARD Science Bowl PHYSICS Physics - 2 PHYS-91; Short Answer: A boy is standing on an elevator which is traveling downward with a constant velocity of 30 meters per second. The boy throws a ball vertically upward with a velocity of 10 meters per second relative to the elevator. What is the velocity of the ball, MAGNITUDE AND DIRECTION, relative to the elevator shaft the instant the boy releases the ball? ANSWER: 20 METERS PER SECOND DOWN PHYS-91; Multiple Choice: Work is equal to which of the following? w) the cross product of force and displacement. x) the product of force times time y) force divided by time z) the dot product of force and displacement ANSWER: Z -- THE DOT PRODUCT OF FORCE AND DISPLACEMENT PHYS-91; Multiple Choice: The work done by a friction force is: w) always positive x) always negative y) always zero z) either positive or negative depending upon the situation. ANSWER: X -- ALWAYS NEGATIVE PHYS-91; Multiple Choice: As defined in physics, work is: w) a scalar quantity x) always a positive quantity y) a vector quantity z) always zero ANSWER: W -- A SCALAR QUANTITY Science Bowl PHYSICS Physics - 3 PHYS-91; Multiple Choice: A pendulum which is suspended from the ceiling of a railroad car is observed to hang at an angle of 10 degrees to the right of vertical. Which of the following answers could explain this phenomena? w) The railroad car is at rest. x) The railroad car is accelerating to the left. y) The railroad car is moving with constant velocity to the right. z) The railroad car is accelerating to the right. ANSWER: X -- THE RAILROAD CAR IS ACCELERATING TO THE LEFT. PHYS-91; Multiple Choice: Two forces have magnitudes of 11 newtons and 5 newtons. The magnitude of their sum could NOT be equal to which of the following values? w) 16 newtons x) 5 newtons y) 9 newtons z) 7 newtons ANSWER: X -- 5 NEWTONS PHYS-91; Short Answer: A ball leaves a girl's hand with an upward velocity of 6 meters per second. What is the maximum height of the ball above the girl's hand? ANSWER: 1.8 METERS PHYS-91; Short Answer: A boy throws a ball vertically upward with a velocity of 6 meters per second. How long does it take the ball to return to the boy's hand? ANSWER: 1.22 SECONDS (accept: 1.2 seconds) PHYS-91; Short Answer: A toy train moves in a circle of 8 meters radius with a speed of 4 meters per second. What is the magnitude of the acceleration of the train? ANSWER: 2 METERS PER SECOND SQUARED PHYS-91; Short Answer: A certain machine exerts a force of 200 newtons on a box whose mass is 30 kilograms. The machine moves the box a distance of 20 meters along a horizontal floor. What amount of work does the machine do on the box? ANSWER: 4000 JOULES Science Bowl PHYSICS Physics - 4 PHYS-91; Short Answer: A box is initially at rest on a horizontal, frictionless table. If a force of 10 Newtons acts on the box for 3 seconds, what is the momentum of the box at the end of the 3 second interval? ANSWER: 30 NEWTON-SECONDS or 30 KILOGRAM-METER PER SECOND PHYS-91; Multiple Choice: A block of metal which weighs 60 newtons in air and 40 newtons under water has a density, in kilograms per meter cubed, of: w) 1000 x) 3000 y) 5000 z) 7000 ANSWER: X -- 3000 PHYS-91; Short Answer: A 10 kilogram body initially moving with a velocity of 10 meters per second makes a head-on collision with a 15 kilogram body initially at rest. The two objects stick together. What is the velocity of the combined system just after the collision? ANSWER: 4 METERS PER SECOND PHYS-91; Short Answer: A certain spring is known to obey Hooke's Law. If a force of 10 newtons stretches the spring 2 meters, how far will a 30 newton force stretch the spring? ANSWER: 6 METERS PHYS-91; Short Answer: A helicopter is ascending vertically with a constant speed of 6 meters per second relative to the ground. At the instant the helicopter is 60 meters above the ground it releases a package. What is the magnitude and direction of the velocity of the package, relative to the ground, the instant the package is released by the helicopter? ANSWER: 6 METERS/SECOND UP Science Bowl PHYSICS Physics - 5 PHYS-91; Multiple Choice: If the distance between two objects, each of mass 'M', is tripled, the force of attraction between the two objects is: w) 1/2 the original force x) 1/3 the original force y) 1/9 the original force z) unchanged ANSWER: Y -- 1/9 THE ORIGINAL FORCE PHYS-91; Short Answer: A 40 kilogram girl climbs a vertical distance of 5 meters in twenty seconds at a constant velocity. How much work has the girl done? ANSWER: 2000 JOULES or 1960 JOULES PHYS-91; Short Answer: A machine performs 8 Joules of work in 2 seconds. How much power is delivered by this machine? ANSWER: 4 WATTS PHYS-91; Multiple Choice: In physics, a radian per second is a unit of: w) angular displacement x) angular velocity y) angular acceleration z) angular momentum. ANSWER: X -- ANGULAR VELOCITY PHYS-91; Multiple Choice: If the resultant force acting on a body of constant mass is zero, the body's momentum is: w) increasing x) decreasing y) always zero z) constant ANSWER: Z -- CONSTANT.