Download PHY 1020 SI PRACTICE FINAL EXAM

PHY 1020 SI PRACTICE FINAL EXAM
Part 1 – Multiple choice
(1) Two objects, one having three times the mass of the other, are dropped from rest at the
same height in a vacuum on the earth. At the end of their fall, their velocities are equal
because:
A) anything falling in vacuum has constant velocity
B) the acceleration of the larger object is three times greater than that of the
smaller object
C) the force of gravity is the same for both objects
D) their accelerations are the same
E) all objects reach the same terminal velocity
(2) The amount of work required to stop a moving object is equal to the:
A) velocity of the object
B) kinetic energy of the object
C) mass of the object times its acceleration
D) mass of the object times its velocity
E) square of the velocity of the object
(3) Two identical carts travel at 1 m/s on a common surface. They collide head-on and are
reported to rebound, each with a speed of 2 m/s. Then:
A) momentum was not conserved, therefore the report must be false
B) if some other form of energy were changed to kinetic during the collision,
the report could be true
C) if the collision were elastic, the report could be true
D) if the surface were inclined, the report could be true
E) if the duration of the collision were short enough, the report could be true
(4) Two bodies of unequal mass, placed at rest on a frictionless surface, are acted on by
equal horizontal forces for equal times. Just after these forces are removed, the body of
greater mass will have:
A) the greater speed
B) the greater acceleration
C) the smaller momentum
D) the greater momentum
E) the same momentum as the other body
(5) In the metric system the standard unit of volume is the liter. A centiliter would be a volume
equal to ______liters.
a) 1,000
b) 100
c) 0.01
d) 0.001
(6) Suppose that the photoelectric effect threshold for a certain metal is in the green portion of
the spectrum. Then ________ light will cause electrons to be emitted from that metal.
a) orange
b) red
c) yellow
d) blue
(7) Einstein's famous equation, E = mc2, is basically a statement that
a) entropy always increases
b) energy is conserved
c) mass and energy are equivalent
d) light has particle-like properties
(8) In the quantum model for the atom, the Maxwell equations describes
a) the energy of the electron
b) the probability of finding the electron in different places
c) the electric and magnetic fields of the electron
d) the electromagnetic force between the nucleus and the electron
(9) In order to explain the daily motions of the sun and stars across the sky, the ancient Greeks
proposed that all celestial objects orbit the Earth about once a day. Their proposal was a
scientific
a) observation
b) hypothesis
c) prediction
d) theory
(10) A car leaves Westfield State and travels to Boston. The main energy transformation that has
taken place as a result of this trip is a transformation from
a) chemical energy to thermal energy
b) kinetic energy to gravitational energy
c) chemical energy to kinetic energy
d) gravitational energy to thermal energy
(11) A charged object is moved up and down. At any other point nearby we can be sure that there
a) is an electric field
b) is a magnetic field
c) are both electric and magnetic fields
d) there won't be a field unless there's another charge at that point
(12) All of the following are vectors, except
a) velocity
b) force
c) acceleration
d) work
(13) Einstein's theory of special relativity replaces Newtonian physics in situations where
a) very small objects are involved
b) objects are located in very strong gravitational fields
c) objects are moving at speeds close to the speed of light
d) very high temperatures are involved
(14) A rock is thrown upward into the air. When it is halfway to its highest point the rock has
a) gravitational energy
b) kinetic energy
c) both gravitational and kinetic energies
d) neither gravitational nor kinetic energies
(15) According to the quantum model of the atom, atoms emit light when
a) an electron jumps from a higher energy level to a lower one
b) a proton jumps from a higher energy level to a lower one
c) an electron jumps from a lower energy level to a higher one
d) a proton jumps from a lower energy level to a higher one
(16) Of the three fundamental particles that make up atoms, the least massive is the
a) neutron
b) proton
c) electron
d) All three particles have equal masses
(17) In the particle model of light, the particles of light are characterized by the amount of energy
they carry and are called
a) baryons
b) photons
c) isotopes
d) molecules
(18) Oxygen is element number 8 on the periodic table. An atom of 18O would contain _____ in
its nucleus.
a) 8 protons and 10 neutrons
b) 8 neutrons and 10 protons
c) 8 protons and 18 neutrons
d) 8 neutrons and 18 protons
(19) 206Bi, a radioactive isotope, has a half-life of about 6 days. If you start out with 400 atoms of
Bi, then after 24 days only about ______will remain.
a) 100 of those atoms
b) 50 of those atoms
c) 25 of those atoms
d) They'd all have been gone after only 12 days
(20) Carbon, mass # =12, atomic# =6, undergoes alpha decay. What is the resulting atom that is
created?
206
(a) 8Be
(b) 16Be
(c) 7N
(d) 8N
(e) 14C
(21) Different isotopes of a chemical element differ in the number of
a) electrons orbiting around the nucleus
b) protons in the nucleus
c) neutrons in the nucleus
d) all of the above
(22) Energy that objects have as a result of their motion is called
a) gravitational energy
b) chemical energy
c) kinetic energy
d) elastic energy
(23) The image you see when you look at yourself in the mirror is
a) real and erect
b) real and inverted
c) virtual and erect
d) virtual and inverted
(24) Refer to the graph on the right. What is the
instantaneous velocity at 8 seconds?
(a) 5m/s
(b) -5m/s
(c) 0m/s
(d) 1m/s
(e) – 1m/s
(25) If a force is applied over a smaller area, the pressure will:
(a) increase
(b) decrease
(c) remain constant
(26) Refer to the following figure: If the current going through the resistor labeled “c” is 2 A,
then what is the voltage through the resistor labeled “A:”
(a)
(b)
(c)
(d)
30 V
300 V
90 V
100 V
Part 2 – True or False:
(1) According to the Second Law of Thermodynamics, the entropy of every object in the
Universe must always increase.
(2) According to modern physics, both matter and light have both wave-like properties and
particle-like properties.
(3) A car moving at a steady 20 miles/hr around a rotary is not accelerating since its speed
remains constant.
(4) An object can have a non-zero distance and a zero displacement.
(5) A current can be induced into a coil by an existing magnetic field.
Part 3 – Short answers:
(1) Suppose that a negatively charged rod was brought near, but not touching, the knob of the
electroscope shown below? What would happen? Why?
(2) An atom of 222Rn undergoes an alpha decay. The product of that decay then beta decays.
What atom do you have left at the end, and what was the intermediate product produced by the
original decay of radon? Explain.
Element # | name
89 actinium (Ac)
88 radium (Ra)
87 francium (Fr)
86 radon (Rn)
85 astatine (At)
84 polonium (Po)
83 bismuth (Bi)
(3) A student throws a rock straight down from a bridge at 15m/s.
a) How fast is it going 3 seconds later?
b) How much distance has it fallen from the top of the bridge after these 3 seconds?