69 Multiple choice questions
- 1. Space objects will move forever once set in motion.
2. Friction and air resistance are the net forces that usually slow objects.
- the force exerted by a fluid depends on the height of fluid above it; the deeper the object, the more pressure.
- force is a __________ quantity.
- µ depends on the _________ of surfaces in contact
- force of surface on object
1.Perpendicular to surface
2. Acts opposite to gravity
- long-ranged but weak; attractive or repulsive force between objects carrying electrical charge.
- your weight in water
(it's less than your weight in air because FB pushes upward)
- inertia is a ___________ quantity
- an object's terminal velocity depends on the object's _____________.
- mass is ____________; weight depends upon the ___________.
- SI units for inertia are _____
- objects don't accelerate downward forever - at some point their velocity becomes _____________.
- Objects behave as particles
Masses of strings are negligible
Interested only in the forces acting on the object
(neglect reaction forces)
- objects accelerating _________ seem heavier.
- If an object's weight > buoyant force, then it ________.
- acts when the object is in motion; f is constant while in motion
- a drawing showing all forces on an object
- a force pushing against a specific area of a surface. (force/area)
- a human's terminal velocity is about 150 mph; an ant's is so low that it can fall far and not get hurt.
- a push or pull
- resistance to motion
- __________ is a measure of inertia
- force on a rope
- *Set the x-axis along the incline and y-axis perpendicular to the incline
*Normal points along y-axis
*Weight points straight down (break into components)
*Friction acts along x-axis
- weight equation
- an object at rest stays at rest and object in motion stays in motion unless acted upon by a net external force.
- ________ scales display the normal force; they are they are the same when a=0.
- The µs and µk are _____________ of the area of contact
- objects accelerating ___________ seem lighter.
- When you apply a force to a confined fluid (a closed system), that pressure is applied equally to all parts of the fluid
- 1. Every action has an equal and opposite reaction
2. Forces always occur in pairs
3. Action and reaction forces must occur on 2 separate objects
4. Equal in magnitude but opposite in direction
- acts to keep the object from moving; if Fa increases, so does ƒs
- the gravitational pull on an object; always points straight down
- very short range and very weak; responsible for radioactive decay.
- the tendency of an object to continue in its original motion (or resist change in motion)
- When the upward Fair resistance = the downward Fgravity, the Fnet = ____.
- strongest force; attractive force that holds the nuclei of atoms together.
If a constant force is applied to an object,
it will ACCELERATE
- describes the relationship between the motion of objects in our everyday world and the forces acting on them
- The direction of the f is opposite the direction of motion
Friction is proportional to the normal n
f = µ n (fyi 0 < μ < 1)
- constant speed
- If an object's weight < buoyant force, then it _______.
- force units are measured in ____________
- the sum of all forces on an object
- *The object is in static equilibrium
*The upward buoyant force is balanced by the downward force of gravity
attractive, and acts between all matter in the Universe; weak, but very
long ranged; it's the dominant force in the universe for shaping
galaxies and stars.
- 1.Balancing forces involves vector addition.
2.The sum of the forces involves considering x- and y-direction forces.
3.Objects in equilibrium have their forces balanced in both x- and y- directions.
- acts upward on an object in a fluid making an object feel lighter.
- the tension on a rope is the __________ at all points on the rope.
- falling objects have 2 forces on them: What are they?
- not moving; a=0
- Pressure is transferred through a fluid.
An applied small Force on a small Area transmits a big Force on a big Area.
Ex: car brakes, car lift
- constant velocity; a=0
- static friction (fs) is ___________ than kinetic friction(fk)
- If the object is more dense than the fluid:
The net force is ______________, so
The object accelerates _________________
- friction is caused by......
- The buoyant force on an object equals the weight of water displaced by the object.
- If the object is less dense than the fluid,
the object experiences a net _____________ force
- What are the four fundamental forces of nature (field)?
- Whether an object sinks or floats depends on the .........
- Means ΣF = 0
there is no acceleration.
(there must be no net torque too)
- factors of friction
- non-moving fluids (ex. pressure, floating)
- gravity, charges, magnets
- moves fluid by changing the pressure in the fluid
- a gas or liquid (both flow)
- If ΣF (net force) = 0, then there is
- caused by 100 km of air above us