Chapter 10 Forces
Terms in this set (62)
push or a pull
In science, a force is a ______________ or a _______________.
When one object pushes or pulls another object, the first object is ____________________ a force on the second object.
The SI unit used to measure the strength of a force is the _______________________.
The overall force on an object after all the forces are added together is called the _______________________________.
When two forces act in the same direction, they are _____________ together.
positive number and a negative number
Adding a force acting in one direction to a force acting in the opposite direction is the same as adding a ____________ number and a ___________ number.
T/F Unbalanced forces acting on an object will change the object's motion.
Equal forces acting on one object in opposite directions are called _____________________________________.
T/F Balanced forces acting on an object will change the object's motion.
0 net force
When you add equal forces exerted in opposite directions, the net force is ____________________.
T/F When two surfaces rub, the irregularities of one surface get caught on those of the other surface.
Friction acts in a direction _________________ to the object's direction of motion.
The force that two surfaces exert on each other when they rub against each other is ___________________.
how hard the two surfaces push together and the type of surfaces involved
The strength of the force of friction depends on what two factors?
Kind of friction when ... an object moved through a liquid or gas.
Kind of friction when ... solid surfaces slide over each other.
Kind of friction when ... an object rolls over a surface.
Kind of friction when ... objects are not moving.
Which kind of friction requires more force to overcome, rolling friction or sliding friction?
What kind of friction occurs when moving parts have ball bearings?
A force that pulls objects toward each other is called _____________.
T/F The force that makes an apple fall to the ground is the same force that keeps Earth orbiting the sun.
Universal Law of Gravitation
Which Law states that the Force of Gravity acts between all object in the universe?
mass of the objects and distance between them
The force of attraction between two objects varies with what two factors?
measure of force of gravity
What is weight?
What unit is weight usually measured in?
T/F On the moon, your mass would be less than it is on Earth, but your weight would be the same.
When the only force acting on an object is the Force of Gravity, the object is said to be in _______________________.
Near the surface of the Earth, what is the acceleration of an object due to the force of gravity?
What is another term for fluid friction when an object is falling through the air?
The greatest velocity a falling objet reaches is called __________________________.
T/F The greater the surface area of an object, the greater the air resistance.
An object that is thrown is called a ___________________________.
T/F An object that is dropped will hit the ground before an object that is thrown horizontally from the same height.
For an unmoving object to start moving, a(n) _______________________________ has to act on it.
The tendency of an object to resist a change in motion is ___________.
Law of Inertia
Newton's First Law is also called the ______________________________.
The amount of inertia an object has depends on its _________________.
F = mass x acceleration
The equation for Newton's 2nd Law is __________________________.
kg * m/s2
What other units can be used to write a N?
increase the force or decrease the mass
What are two ways to increase the acceleration of an object?
an object at rest will stay at rest and an object in motion will stay in motion, until acted upon by an outside force
Summarize Newton's 1st Law of Motion ...
F = m*a
Summarize Newton's 2nd Law of Motion ...
for every action, there is an equal and opposite reaction
Summarize Newton's 3rd Law of Motion ...
What is the name given to the force exerted by the first object on a second object?
What is the name given to the force exerted by the second object back on the first object?
equal and opposite
The action and reaction forces in any situation will always be ______________ and ________________.
they are acting on different objects
Why do the equal and opposite action and reaction forces no cancel each other out when a person hits a ball?
The product of an object's mass and velocity is its _______________________.
mass X velocity
What is the equation to calculate momentum?
kg * m/s
What is the unit of measurement for momentum?
in the absence of outside forces, the total momentum of objects that interact does not change.
What does the Law of Conservation of Momentum state?
Newton's 3rd Law
Which of Newton's laws explains the lifting of a rocket into space?
Action: fuel is burned and exhaust pushes gas down
Reaction: the gas pushes back on the rocket lifting it up
What are the equal and opposite forces that allow a rocket to lift off?
Any object that travels around another object in space is a(n) _________________________.
An object traveling in a circle is accelerating because it is constantly changing _________________________.
What is a force called that causes an object to move in a circle?
gravitational pull toward the Earth
For a satellite, what is the centripetal force that causes it to move in a circle?
T/F: Satellites in orbit around the Earth continually fall toward the Earth.
A satellite is a projectile that falls _________ Earth rather than into Earth.
Why doesn't a satellite need fuel to keep moving?
What force continually changes a satellite's direction?