Terms in this set (23)
the force that one surfaces exerts on another when two surfaces rub against each other
friction that acts on objects that are not moving (to get an object to start to move, you must exert a force greater than this force)
friction that occurs when one solid surface slides over another (once an object is moving, this force acts oppositely to the motion of the objects SLIDing against the other)
friction that occurs when an object rolls over a surface (once an object is moving, this force acts oppositely to the motion of the objects ROLLing against the other)
friction that occurs as a solid object moves through a fluid (once an object is moving, this force acts oppositely to the motion of the objects pushing fluid aside)
the force that pulls objects twords each other
the amount of matter in an object
the force of gravity on an object at the surface of a planet
the motion of a falling object when the only force acting on it is gravity
the fluid friction experienced by objects falling through the air
the greatest velocity a falling object can achieve
an object that is thrown
4 types of friction
What is the difference between weight & mass?
•weight is the force of gravity on an object
•mass is the amount of matter of an object
How does gravity affect objects that are moving horizontally?
the force of gravity acts on objects moving horizontally the same as an object in free fall
What types of friction occur when riding a bike through a puddle?
rolling and fluid friction
law of universal gravitation
force of gravity acts between all objects in the universe
How do mass & distance affect the gravitational attraction between objects?
•increased mass causes increased gravitational attraction between objects
•increased distance causes decreased gravitational attraction between objects
What happens to the force of gravity when mass increase? When distance increases? When distance decreases?
•increase force of gravity when increase mass
•decrease force of gravity when increase distance
•increase force of gravity when decrease distance
How would your weight change on the surface of an Earth-sized planet whose mass was greater than Earths' mass? Why?
•the distance between 2 objects (planet surface and me) stay the same,
•but the mass increases for one of the objects, so the weight (or force of gravity) would increase
Why does an object accelerate when it falls toward the Earth's surface?
in free fall the force of gravity is an unbalanced force, which causes an object to accelerate
How does the mass of an object affect its acceleration during free fall?
all objects accelerate at the same rate during free fall, no matter what their mass is
What force changes when a sky diver's parachute opens? What force stays the same?
•air resistance changes and
•gravity stays the same