Flashcards
8th grade Science Forces & Gravity
Cards in this deck (36)
- 1What was Newton's Second Law?it describes how force, mass, and acceleration are related.
- 2What is the formula for acceleration?acceleration=force/mass
a=f/m
F=m*a - 3What is Friction?The force that opposes the sliding motion of the two surfaces that are touching each other.
- 4What is the force that opposes most motion?friction
- 5How does Newton's 2nd law prove his first law?If the force is 0 that means an object at rest is staying at rest and an object that is moving will continue moving at the same speed.
- 6The amount of friction between 2 surfaces depends on what 2 factors?1) the kinds of surfaces
2)the force pressing the surfaces together. - 7What are microwelds?They are kinds of surfaces
- 8What is the frictional force that prevents two surfaces from sliding past each other?Sliding Friction
- 9What is the frictional force that opposes ttwo surface from sliding past each other?Sliding Friction
- 10What is the frictional force between a rolling object and the surface it rolls on ?rolling friction
- 11What is the friction-like force that opposes the motion of objects that move through the air (depends on the speed, size, & shape of the object)air resistance
- 12What is the highest speed a falling object will reach before air resistance= the acceleration due to gravity?called terminal velocity
is 9.8 m/s - 13what is an attractive force between any 2 objects that depends on the masses of the objects and the distance between them?Gravity
- 14What are the 4 basic forces of gravity?1) Gravity
2) Electromagnetic force
3) strong nuclear force
4) weak nuclear force - 15what calculates the force of gravity between 2 objects if their masses and distance between them is knownthe law of universal gravitation
- 16What is the formula for force?F=G m1m2/d2
- 17what is the acceleration of falling objects on Earth due to the force of gravity?9.8m/sec2
- 18What is the property called that is related to how much force is needed to change the motion of an object?Momentum
- 19What is the formula for momentum?momentum (p)= mass (m) * velocity (v)
p=mv - 20This is not a question - it is an assignment - please do the practice problems on p.86this answer can only be right after you have done these
- 21Momentum is not created nor destroyed - it just changes forms (or gets transferred from one object to another) - What is this law called?The Law of Conservation of Momentum
- 22the formula to find the force of Earth's gravity will always be....Force of gravity (N) = mass (kg)*acceleration
- 23Acceleration due to gravity is always how much?9.8 m/s2
- 24What would the gravitational force be on a sky diver with a mass of 60kguse your formula to solve!
- 25How do you calculate weight of something or someone on earth? (formula)Weight = mass x 9.8m/sec2
- 26What do we call the gravitational force on a mass?it's weight
- 27Why do astronauts appear to be weightless in space?a space shuttle is in free fall but it is falling around the Earth rather than straight downward (see fig 15 pg 79)
- 28How are horizontal & vertical motions affected by gravity?check out you textbook - p. 80, fig 16 & 17
- 29The net force exerted toward the center of a curved path is calledcentripetal force
- 30What force keeps your car's traction moving around a curved path?Centripetal Force
- 31acceleration toward the center of a curved path is _____centripetal acceleration
- 32State Newton's 3rd Law of MotioinFor every action force, there is an equal and opposite reaction
- 33Give 2 examples of Newton's 3rd law in action1) rocket propulsion
2) skaters pushing against a wall and moving backward (p. 83, fig 21) - 34What is a property that is related to how much force is needed to change the motion of an object?Momentum
- 35What Law says that momentum is not created nor destroyed it just changes forms ( or gets transferred from one object to another) ?Law of Conservation of Momentum
- 36What is the law for Momentum?p(momentum)=m(k/g) times v(m/s)
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- study guide - 8th grade science motion & forces
- Created by
- Pisgah · Oct 2015
- Updated
- Jan 18, 2017
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