Physics 7 (Winter 08) – Homework #1

Due: 1/15

 

1.      Why should scientific theories be falsifiable?

2.      One should trust scientific theories

a)      Based on the logic of the arguments provided to support them

b)      Only to the extent that they are supported by the experimental data

c)      According to whether they are simple or not

d)     Only if they agree with existing ideas

e)      Only to the extent that they don’t go against common sense

3.      Occam’s razor is useful because

a)      It provides a really close shave

b)      It explains how to tell if a hypothesis is related or not to what we are looking at

c)      It always selects the simplest description of Nature

d)     It tells which theories are absolutely true

4.      Uri Geller’s claimed ability to bend spoons by gently rubbing them was debunked because

a)      He is not a scientist

b)      The average guy in the street could not do it

c)      It would require a revision of the accepted laws of physics

d)     Because it could not be done using thick metal rods

e)      Because Geller himself could not do it in the environment of a controlled experiment

5.      According to Aristotle a balloon hovering in mid air does so because

a)      Gravity is balanced by the balloon’s buoyancy

b)      It is partly fiery and partly earthy in character so that the opposing natural motions cancel

c)      It natural motion downward is balanced by tits buoyancy

d)     Its natural motion upward is balanced by gravity

e)      Of unknown reasons: he would simply have no explanation.

6.      A spacecraft on the way to the Moon turns off its rockets half-way, in the vacuum of space. According to Aristotle,

a)       It will coast towards the Moon

b)      It will start orbiting the Moon

c)      It will eventually fall back towards Earth, moving at infinite speed as long as it is outside the atmosphere.

d)     It will start orbiting the Earth

7.      As the Eagle (the landing craft form the Apollo 11) approached the Moon it turned around so that its rockets pointed toward the lunar surface. According to Aristotle what would have happened as this maneuver was completed?

a)      The rockets would slow down the Eagle’s approach to the Moon making a soft landing possible

b)      The Eagle would start speeding towards Earth and away form the Moon

c)      The Eagle would have started orbiting the Moon since that is its natural motion

d)     The Eagle would have started moving towards the Sun because that is its natural motion

e)      The Eagle would have hovered above the Moon indefinitely because the pull from the Moon’s gravity is balanced by the natural motion towards Earth.

8.      When an ox stops pulling a cart the cart stops. According to Aristotle this is because

a)      Horizontal motion of the cart is not “natural” and so it can occur only if something (in this case the ox) generates it.

b)      Frictional forces make it stop

c)      The cart is mainly made of fire and so its natural motion is upward (being kept on the ground only be its contents)

d)     The gravitational force from the Earth anchors it to the ground.

e)      The natural motion of the ox is forward while that of the cart is backward, so they both stay put.

9.      One belief of Pythagoras that has survived to this day is that

a)      Planets move in circles around the Sun

b)      There is an additional planet, the “counter Earth”, which we know as Venus.

c)      Mathematics described Nature

d)     The number 10 is special among all numbers

e)      Striking an anvil makes a sound similar to the music of the spheres.

10.  According to Pythagoras as heavenly bodies move they

a)      Indicate that they are mainly made out of fire

a)      Emit a sort of heavenly music

b)      Indicate that they are mainly made out of earth

c)      Circle the sun

d)     Eventually come together into a single body since 1 is the most important number