PHYS 131 EXAM 1 QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED
A+||BRAND NEW
============ GRAVITY =============== - ANSWER-============ GRAVITY ===============
What is Newton's First Law? - ANSWER-An object at rest stays at rest and an object in motion stays in
motion with the same speed and in the same direction unless acted upon by an outside force.
An object at rest, or in motion in a straight line at a constant speed, will ___________ unless
____________. - ANSWER-remain in that state
acted upon by a force
If the Sun disappeared, the Earth would ____________ its orbit at that time. - ANSWER-continue in the
direction that it was traveling in
The ____________of a body due to a force will be in the same direction as the force, with a
____________ directly proportional to its mass. - ANSWER-acceleration
magnitude
Force = ____________ x ____________
a ____________ mass will move faster if the same force is applied to it - ANSWER-Force = mass *
acceleration
smaller
,For every action there is an ____________ and ____________ reaction - ANSWER-equal
opposite
The Sun exerts force on planets and they orbit it - the planets exert ____________ force on the Sun, but
it only moves slightly because of its very ____________ mass relative to the planets - ANSWER-equal
large
The strength of gravity, g, on the surface of a planet is given by
g = _______ / _______^2
where ________ is the ________ and ________ is its _________. - ANSWER-M, R
M, mass, R, radius
Note that the RADIUS IS SQUARED, but mass is not
More ____________ = More ____________
If the ____________ of a planet were twice that of another, and they have the same radius, the
____________ of the more massive planet is two times as strong - ANSWER-mass, gravity
mass, gravity
Less ____________ = Less ____________
, If the ____________ of a planet were twice that of another, the gravity is 1 / (2)^2 = 1/4 as strong -
ANSWER-separation, gravity
radius
Putting the effects of mass and radius together, you should be able to figure out the surface gravity of
Mars, relative to the Earth. Mars has 1/10 the mass of the Earth and 1/2 the radius of Earth.
So for Mars,
g = ____________ - ANSWER-g = (1/10) / (1/2)^2 = (1/10) / (1/4) = 4/10
Mars has a surface gravity of 4/10 that of Earth.
What is Newton's Universal Law of Gravitation? - ANSWER-This law gives the force of gravity between
any two objects in the Universe.
Newton's Universal Law of Gravitation says that the force of gravity is proportional to ____________:
F = (M1 x M2) / d^2
Again, more ____________ = more ____________
If the objects were moved 2 times closer (or, to half of their initial distance between):
F = ____________,
in other words, the gravitational attraction would become ____________ - ANSWER-(mass of obj 1) x
(mass of obj 2) divided by the distance between the two objects squared
mass, gravity
ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED
A+||BRAND NEW
============ GRAVITY =============== - ANSWER-============ GRAVITY ===============
What is Newton's First Law? - ANSWER-An object at rest stays at rest and an object in motion stays in
motion with the same speed and in the same direction unless acted upon by an outside force.
An object at rest, or in motion in a straight line at a constant speed, will ___________ unless
____________. - ANSWER-remain in that state
acted upon by a force
If the Sun disappeared, the Earth would ____________ its orbit at that time. - ANSWER-continue in the
direction that it was traveling in
The ____________of a body due to a force will be in the same direction as the force, with a
____________ directly proportional to its mass. - ANSWER-acceleration
magnitude
Force = ____________ x ____________
a ____________ mass will move faster if the same force is applied to it - ANSWER-Force = mass *
acceleration
smaller
,For every action there is an ____________ and ____________ reaction - ANSWER-equal
opposite
The Sun exerts force on planets and they orbit it - the planets exert ____________ force on the Sun, but
it only moves slightly because of its very ____________ mass relative to the planets - ANSWER-equal
large
The strength of gravity, g, on the surface of a planet is given by
g = _______ / _______^2
where ________ is the ________ and ________ is its _________. - ANSWER-M, R
M, mass, R, radius
Note that the RADIUS IS SQUARED, but mass is not
More ____________ = More ____________
If the ____________ of a planet were twice that of another, and they have the same radius, the
____________ of the more massive planet is two times as strong - ANSWER-mass, gravity
mass, gravity
Less ____________ = Less ____________
, If the ____________ of a planet were twice that of another, the gravity is 1 / (2)^2 = 1/4 as strong -
ANSWER-separation, gravity
radius
Putting the effects of mass and radius together, you should be able to figure out the surface gravity of
Mars, relative to the Earth. Mars has 1/10 the mass of the Earth and 1/2 the radius of Earth.
So for Mars,
g = ____________ - ANSWER-g = (1/10) / (1/2)^2 = (1/10) / (1/4) = 4/10
Mars has a surface gravity of 4/10 that of Earth.
What is Newton's Universal Law of Gravitation? - ANSWER-This law gives the force of gravity between
any two objects in the Universe.
Newton's Universal Law of Gravitation says that the force of gravity is proportional to ____________:
F = (M1 x M2) / d^2
Again, more ____________ = more ____________
If the objects were moved 2 times closer (or, to half of their initial distance between):
F = ____________,
in other words, the gravitational attraction would become ____________ - ANSWER-(mass of obj 1) x
(mass of obj 2) divided by the distance between the two objects squared
mass, gravity
