Answers to Physics Concept Questions - Test #2
  1. You accelerate. The speed of your car doubles. Which of the following items quadruples as a result?
    1. momentum
    2. potential energy
    3. acceleration
    4. kinetic energy
    5. all of these
    6. none of these
  2. Two railroad cars move towards each other at 10 m/s. They collide and bounce backward at 20 m/s. This event violates conservation of
    1. mass
    2. acceleration
    3. kinetic energy
    4. potential energy
    5. collisions
    6. none of these
    7. all of these
  3. A certain car has momentum. It therefore must also have
    1. acceleration
    2. kinetic energy
    3. force
    4. potential energy
    5. impulse
    6. none of these
    7. all of these
  4. A 100 Newton force is used to push a table by 5 meters. The amount of work done on the table is
    1. 5 J
    2. 100 J
    3. 0 J
    4. 500 J
    5. 1000 J
  5. A meteor moving at 30 m/s collides with a twice-as-massive meteor and sticks to it. After the collision, the combined meteors have a kinetic energy that is ___ as much as the total kinetic energy before the collision.
    1. the same
    2. twice
    3. one third
    4. three quarters
    5. two thirds
    6. not enough information
  6. A farmer replaces the tires on his tractor with smaller diameter tires. For a given RPM, the linear speed of the tractor is now
    1. the same as before
    2. more
    3. less
    4. all of the above
    5. none of the above
    6. not enough information
  7. Based on rotational inertia, which will take longer to roll down an incline… a can filled with ice, or the same can filled with water?
    1. ice
    2. water
    3. both the same
    4. depends on the size of the can
    5. depends on the temperature of the water
    6. not enough information
  8. If you kick a football so that the force of your kick passes through its center of gravity. As it flies through the air, the football will
    1. not move
    2. rotate clockwise
    3. rotate counter-clockwise
    4. rotate from left to right
    5. not rotate
    6. not enough information
  9. As you slow down your car, the rotational speed of your tires is halved. The linear speed of a bug sitting at the edge of your tire will
    1. double
    2. quadruple
    3. stay the same
    4. be halved
    5. be reduced to a quarter
  10. During an ice age, the polar ice caps grow in size and the water-level drops in the oceans all around the earth. This redistribution of mass will cause the earth's day to become
    1. longer
    2. shorter
    3. stay the same
    4. the earth will stop rotating
    5. not enough information
  11. If the mass of the sun and the earth are both tripled, and the distance between them is also tripled, the force between them will be
    1. doubled
    2. halved
    3. tripled
    4. one third
    5. the same
    6. nine times
    7. one ninth
  12. You don’t see tides in your swimming pool. This is because
    1. your contact lenses are missing
    2. magnetic forces hold the water down
    3. the pool is too shallow for tides
    4. the pool is too deep for tides
    5. the tides happen at night when you are asleep
    6. all parts of the pool are at about the same distance to the moon
  13. The distance between the earth and the moon is reduced to one third. The gravitational force between them becomes
    1. 3 times bigger
    2. 3 times smaller
    3. 9 times bigger
    4. 9 times smaller
    5. stays the same
  14. What keeps the earth from falling into the sun?
    1. strings hold the earth up
    2. gravity holds the earth up
    3. the earth's tangential speed
    4. smoke and mirrors
    5. the sun's gravity is zero where the earth is
  15. What is a black hole ?
    1. a hole in your dry-wall
    2. space with no stars
    3. space with no light
    4. space with no mass
    5. a space with mass so highly concentrated that even light cant escape the resulting gravity
  16. A ball is thrown horizontally. After it has left the thrower's hand, what is the acceleration that it experiences ?
    1. an acceleration of - 1 g horizontally
    2. an acceleration of + 1 g horizontally
    3. 1 g downward
    4. 1 g upward
    5. no acceleration
  17. A pitcher drops a ball. At the same instant, another ball is thrown at an angle of 5 degrees below the horizontal. Which ball will hit the ground first ?
    1. the dropped ball
    2. the thrown ball
    3. both reach at the same time
    4. the dropped ball turns into a banana and flies away
  18. A meteor is captured by earth's gravitational field and goes into elliptical orbit around the earth. Compared to when the meteor is far from the earth, its speed when it is close to the earth is
    1. the same
    2. faster
    3. slower
    4. not enough information
    5. depends on whether today is Tuesday or Thursday
  19. A student throws a ball horizontally from the top of a 20 meter tall building. The ball hits the ground 20 m from the building. What was the students pitching speed?
    1. 20 m/s
    2. 1 m/s
    3. 5 m/s
    4. 10 m/s
    5. not enough information
  20. What keeps the moon from falling?
    1. earth's gravity is zero near the moon
    2. earth's gravity is balanced by the sun's gravity
    3. strings, smoke and mirrors
    4. magnetic forces
    5. electrical forces
    6. the moon is falling around the earth
  21. Why are the atoms in a baby's body about the same age as the atoms in an adult's body? Because…
    1. Inside every baby is an adult
    2. Inside every adult is a baby
    3. Atoms are eternal, i.e., they always existed
    4. All atoms and elements were formed at the Big Bang, about 14 billion years ago
    5. Atoms, that are present in both baby and adult, were formed about the same time by exploding stars
  22. Most of the mass of an atom is in its
    1. electrons
    2. massons
    3. atomic mass units
    4. protons and neutrons
    5. miceons
  23. The atoms in your body are mostly empty space, and so are the atoms in any wall. Why then is your body unable to pass through walls ? Because of…
    1. absence of doors in the walls
    2. magnetic forces between atoms
    3. nuclear forces
    4. gravitational forces
    5. electrical forces
    6. atomic vibrations
  24. Which of the following is a mixture?
    1. water
    2. carbon-dioxide
    3. methane
    4. air
    5. salt
    6. sugar
    7. none of the above
    8. all of the above
  25. When sodium and chlorine react to form salt, a certain amount of energy is given off. This energy is ___ compared to the energy it takes to separate sodium and chlorine to form salt.
    1. less
    2. more
    3. the same
    4. it is impossible to separate sodium and chlorine from salt
  26. Which has more surface area?
    1. a whole potato
    2. a potato cut into four quarters
    3. a potato cut into Freedom fries (ex-French fries)
    4. all of these have the same surface area
  27. Doubling the length of the sides of a cube multiplies its volume by
    1. 2 and its surface area by 1
    2. 4 and its surface area by 2
    3. 6 and its surface area by 3
    4. 8 and its surface area by 4
    5. does not change its volume
  28. Halving the diameter of a rope will multiply its strength by
    1. 1
    2. 1/2
    3. 1/4
    4. 1/8
    5. 2
    6. 4
    7. not enough information
  29. Which has greater surface area for a given body weight (i.e., greater surface area per unit weight)
    1. a snake
    2. an elephant
    3. a bowling ball
    4. a piece of string
    5. not enough information
  30. An object has a mass of 60 kg and a density of 30 kg per cubic meter. What is the volume of the object?
    1. 1800 cubic meters
    2. 2 cubic meters
    3. 30 cubic meters
    4. 60 cubic meters
    5. not enough information

PHYSICS WORLD .ORG
Test-2 | Home | Contact