PHYSICS FINAL - NEWTON's LAWS
the mass of a child who weighs 50 N on Earth is about?
5 kg
three forces are acting on an object. The object is not moving. One force is 2N left and the other force is 5N left. What is the third force?
7N
A 2.0 kg book rests motionless on a table top. In this case, the book's weight is balanced by?
A normal force
Galileo's conclusions about motion helped advance science because they were based on
experiments rather than philosophical discussions.
any influence that tends to accelerate an object
force
the force that acts to resist he relative motion of objects in contact with each other
friction
the force that moves the horse-cart system is
friction by the ground on the horse's feet.
space is?
frictionless
he weight of something is closely related to
gravity
if you apply more force to an object it accelerates at a ___ rate
higher
the state of an object or systems of object for which no physics changes occur
mechanical equilibrium
A sledgehammer is used to apply a force on a physics teacher who lies sandwiched between two beds of nails. This demonstration could be made safer if the beds contained
more nails
When you jump vertically upward, strictly speaking, you cause Earth to
move downward.
the vector sum of all the forces that act on an object
net force
According to Aristotle, motion is
of two types
A cart is pushed and undergoes a certain acceleration. If the force is held constant and the mass of the cart doubles, its acceleration would be
one half
The team that wins in a tug-of-war is the team that
pushes hardest on the floor
The force that directly propels a vehicle along a highway is provided by the
road
Anna and Marie go sky diving. Anna is heavier than Marie, but both use the same size parachute. Anna has a greater terminal speed compared with Marie because
she has to fall faster for air resistance to match her weight.
A falling object that reaches terminal velocity continues to have
speed
When you toss a rock straight upward, which is no longer present at the top of its path?
speed
If you swing string with a stone attached overhead in a horizontal circle, and the string breaks, the tendency of the stone is to follow a
straight lined path
A boulder falls due to gravity. The reaction force on the boulder is
the boulder pulling up on Earth.
A bird can drop from a tree branch and reach the ground below because
the branch, tree, and ground move at the same speed.
Newton's first law is illustrated by
the equation ∑F = 0.
A heavyweight boxing champion CANNOT hit a piece of tissue paper in midair with much force because
the paper can't produce much opposite force.
A cart is pushed and undergoes a certain acceleration. If it were pushed with twice the force while its mass doubles, its acceleration would be
the same
When you stand on one foot instead of two, the force you exert on the ground is
the same
When a net force acts on an object, its acceleration depends on the object's
mass
A system undergoes acceleration only when acted on by
a net force
Which has the greatest volume compared with 1 kilogram of bananas?
1 kilogram of feathers
Use Newton's second law to answer this question: The acceleration of a vertically thrown ball at the top of its path is
10 m/s 2
When you drop a ball it accelerates downward at 10 m/s2. If you instead throw it downward, then its acceleration immediately after leaving your hand, assuming no air resistance, is
10 m/s 2
A vampire with a mass of 60 kg will have a mass of ___ on a different planet where a g = 20 m/s2
1200 N
On Earth, a 20 kg object will have a weight of?
200 N
what is the weight of an object on Earth if its mass is 25kg?
250 N
A tow truck exerts a net force of 3000N on a car, accelerating I️t at 10 m/s2. What is the mass of the car?
300 kg
A karate chop delivers a force of 3000 N to a board that breaks. The force that the board exerts on the hand during this event is
3000 N
When a student sits in a desk, there is a pair of forces acting between the student and the desk. This is best explained by?
Action - Reaction ?
While floating in outer space you throw a ball. The ball then?
Continues at a constant speed in a straight line forever
Who reasoned that the Earth and the other planets were moved around the sun?
Copernicus
The first scientist to be credited with the idea that Earth moves around the sun was
Copernicus.
At a constant net force, the relationship between mass and acceleration is?
Directly proportional
Newton's Second Law?
EF = ma
Earth pulls on the moon. Similarly, the moon pulls on Earth. We can say that
Earth and moon are pulling on each other.
If you push against a wall, the wall pushes back at you with, _____ force and ____ direction
Equal, opposite
EF = 0
Equilibrium rule
T or F inertia is directly related to volume
F
T or F weight depends on location
F
Two books are laying on a table top. Without picking them up how could you determine which has a greater inertia?
Give each one a push, and the one that moves easiest has less mass
AN automobile and a gold cart traveling at the same speed collide head-on. The impact force is the?
Greater on the automobile
How hard a boxer's punch lands depends mostly on the
How hard a boxer's punch lands depends mostly on the
Objects resist changes to its state of motion due to its?
Inertia
Compared to a 1 kg block of solid iron, a 2 kg clock of solid iron has twice as much?
NA (interim, mass, volume, all, none?)
mass is?
matter / inertia
When you stand on the floor you are pulled by gravity, and supported upward by the floor. The force of gravity pulling down and the support force pushing up _____
NA (make an action-reaction pair of forces, do not make a reaction-action pair of forces, are not in equilibrium, need more equilibrium, causes you to accelerate?)
an object continues in its state of rest, or in its state of uniform motion, unless acted on by an unbalanced force
Newton's Second Law
SI unit for force
Newtons
T or F you have a net force of 0 when you are in equilibrium
T
T or F an object at rest always wants to stay at rest
T
T or F force is a vector
T
To say the weight of an apple is 1N is to say that a downward gravitational force of 1N is exerted on the apple by?
The Earth
The force due to gravity on an object is the object's?
Weight
A math book and a physics book are tied together with a length of string. With the string taut, one book is pushed off the edge of a table. As it falls, the other book is dragged horizontally across the table surface. With no friction, acceleration of the books is
a value between zero and g.
If a net force acts on a horse while it is pulling a wagon, the horse
accelerates
think of gravity as a ?
action reaction pair
for every __ there is an equal and opposite ___
action, reaction
When a cannonball is fired from a cannon, both the cannonball and the cannon experience equal
amounts of force
Newton's First Law
an object will remain at rest unless acted on by an outside force
The Earth moves about 30 km/s relative to the sun. When you jump upward in front of a wall, the wall doesn't slam into you at 30 km/s. This is because the wall
and you are moving at the same speed, before, during, and after your jump.
One kilogram of matter weighs 10 newtons
at Earth's surface.
When standing in the aisle of a smoothly moving bus, you drop a coin from above your head. The falling coin will land
at your feet
Consider a ball resting in the middle of a cart. When you quickly jerk the cart forward, the
back of the cart hits the ball.
The net force on a kicked football can be zero when it is kicked
by two feet with equal and opposite amounts of force.
The quantity of matter in an object
mass
When an air-filled balloon is untied and air escapes, the balloon shoots through the air. The force that propels the balloon is provided by the
ejected air
When you increase the net force on a shopping cart its acceleration
increases
The force of air friction against a falling sack of potatoes
increases with increased speed.
the property of things to resist change in motion
inertia
Whenever one object exerts a force on a second object, the second object exerts a force on the first that
is equal in magnitude
an object will accelerate when
it is pushed or pulled with a net force.
When we say that 1 kilogram weighs 10 newtons, we mean that
it's true at Earth's surface.
The force that propels a rocket is provided by
its exhaust gases.
SI unit for mass?
kg
inertia measures?
laziness
A tennis ball filled with lead and a regular tennis ball are dropped from the top of a tall building at the same time. Both encounter air resistance. Which reaches the ground first?
lead filled tennis ball
The weight of 1 kilogram of iron on Earth will weigh
less on the moon
A 20-N object falling with 5 N of air resistance has an acceleration
less than g
weight depends on?
location
If an object has more mass it accelerates at a ___ rate
lower
The concept of inertia mostly involves
mass
The mass of 1 kilogram of iron on Earth will be
the same on the moon
A massive truck and a golf cart have a head-on collision. The least amount of acceleration occurs for
the truck
When a squid pushes against water, the squid moves forward because
the water pushes against the squid.
A force interaction involves
two forces
We aren't swept off the fast-moving Earth because
we move along with it in accord with the law of inertia.
the force due to the gravitational attraction of another body
weight
If a 10-kg rock and 5-kg rock are dropped from the same height, at the same time, and in the absence of air resistance, then they will fall
with the same acceleration
