Physics Unit 4
The law of inertia states that an object...
-at rest will remain at rest unless acted on by an outside force -will continue moving at the same velocity unless an unbalanced force acts on it -will continue moving in a straight line unless an unbalanced force acts on it
your textbook weighs 2N. When held at rest above your head, the net force of the book is ...
0N
The mass of a pet turtle that weighs 10 N is about
1 kg
a jet has a mass of 100,000kg. each engine has a force of 50,000N. What is the jet's acceleration in m/s^2
1 m/s^2
How much inertia would a 1 kilogram mass of feathers have compared to a 2 kilogram mass of feathers?
1/2 as much
if the acceleration of gravity on jupiter is 3x that on earth, what will the mass of 10kg of copper be on jupiter?
10kg (mass doesn't change)
an object is pulled up with two forces of 20N and 35N. however, gravity pulls down on it with 40N. Find the net forces size and direction
15N going up
a 10N and 5N force are working on an object in the same direction. the mass is 5kg. what is the acceleration
3 m/s^2
mass of something that weighs 56N
5.7kg
A 4kg object has 35N pulling to the right, 20N pulling up, 5N pulling to the left. find its acceleration and direction
9.0m/s^2 at 33.7 degrees north of east
what is the weight of 1kg mass
9.8N w=mg
the metric unit of weight is the
Newton
newton's second law states that
a=F/m
this quantity measures the rate of change of velocity.
acceleration
true or false Whenever an object exerts a force on another object, the second object exerts a force of the same magnitude, but in the opposite direction to that of the first object.
always true
what has no change in its state of motion
an object at equilibrium an object at rest an object at constant speed
if an object's mass is increasing while a constant force is applied to the object, the acceleration _________
decreases
true or false according to newton's third law, when an object exerts a force on another object, the second object exerts a reaction force equal and opposite on yet another force
false
true or false if a hockey puck slides on a perfectly frictionless surface, it will eventually slow down because of its inertia.
false
true or false the letter "g" is the symbol for force due to gravity
false g= -9.8 m/s^2 =acceleration
accelerations are produced by
forces
according to newton's third law, if you push gently on something, it will push...
gently on you
forces always occur
in pairs
An objects resistance to a change in its state of motion.
inertia
what is the only quantity that affects the amount of inertia something has
mass
For every action there is an equal and opposite reaction
newton's third law
what are the english units to measure mass
slugs
when an object falls through a vacuum, its velocity increases and its acceleration ________
stays the same
As a ball falls, the action force is the pull of Earth's mass on the ball. What is the reaction to this force?
the pulls of the ball's mass on the earth
a bug splatters against the window of a moving car. compared to the force of the car on the bug, the force of the bug is...
the same size
Which has more mass, a kilogram of feathers or a kilogram of iron?
they are the same
true or false an objects weight depends on it's location, but it's mass does not
true
true or false inertia is the resistance any material object has to a change of state of it's motion
true
