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44 Cards in this Set
- Front
- Back
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Define mass |
The quantity of matter in an object.
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Define weight
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The force of gravity on an object.
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What is the difference between mass and weight?
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They are directly proportional but mass does not depend on gravity and weight does.
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Why do objects in motion usually stop moving?
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Friction or any outside, non-zero force.
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What direction does friction always act?
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Opposite of motion
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Define friction
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The resistive force that opposes the motion or attempted motion of an object
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Define velocity
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Speed and direction of an object
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In free fall, which will fall faster: a rock or a feather?
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They will fall at the same rate.
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In free fall, with the rock and the feather, is the gravitational force greater on one than the other?
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Yes, it is greater on the rock because its mass is larger.
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Newton's 1st Law of Motion
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Law of inertia: every object continues in a state of rest or of uniform speed in a straight line unless acted upon by a non-zero force
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Newton's 2nd Law of Motion
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Law of Acceleration: F=ma, acceleration produced by a net force on an object is proportional to the net force
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Newton's 3rd Law of Motion
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Equal and Opposite Forces: objects exert equal forces on one another
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What is g? What is it's value?
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g = acceleration due to gravity; 9.8 m/s2
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Define terminal speed
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When air resistance is equal to mass and acceleration stops
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What does mass times velocity equal?
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Momentum (MaVmentum)
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Define energy
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The ability to do work
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Is energy a conserved quantity?
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Yes, energy cannot be created or destroyed.
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Besides energy, what other quantity is conserved?
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Momentum
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If you lift a 20 lb. box over your head, hold it there for 10 seconds and put it back down in the same spot, how much work have you done?
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None, work depends on position from start to finish.
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What is the difference between potential and kinetic energy?
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Potential energy relies on an object's position. Kinetic energy depends on an object's movement.
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Where does the law of gravity work?
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Everywhere
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Explain how centripetal forces works.
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Centripetal forces are any force that pulls a moving object towards the center of the motion. Ex. gravity pulling the moon in a circular orbit.
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State the Law of Universal Gravitation (formula)
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Force = G(mass1 x mass2)/distance2. Everybody in the universe attracts every other body with a mutually attracting force.
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What is the inverse-square law?
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Law relating the intensity of effect to the inverse square of the distance from the cause: 1/d2
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What happens to the force of gravity between Earth and a rocket when the distance between them is doubled? Tripled? Halved?
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"Doubled = force is 1/4 as much Tripled = force is 1/9 as much Halved = force is 4 times as much"
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What characteristic separates science from other disciplines?
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It is empirical - based on experiments
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Define impulse and explain where it comes from
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Impulse is a change in an object's momentum and it results from a force acting over a period of time
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Does an object in motion require a force to keep it moving (no friction)?
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No
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What do we call the tendency to resist changes in motion?
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Inertia
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What is force?
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Push or a pull
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What role does friction play?
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Opposes motion
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How are position, velocity, and acceleration related?
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Their slope
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Why do we say centrifugal forces are fictitious?
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No force is actually trying to pull you out.
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What is the third law pair?
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The earth pulls on you, you pull on the earth.
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What is a vector?
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A change in direction and magnitude.
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What is energy?
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The property of a system that enables it do work. Measured in joules. SI unit = joules
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What is work?
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The product of the force and the distance through which the force moves. Work = force x distance. SI units = Joules (newton-meter)
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What is power?
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The time rate of work or power is the rate at which energy is used. SI unit = Watts, Power = work/time
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What does it mean when a quantity is conserved?
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It is not lost or does not change. Momentum and total energy.
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Why do we feel weightless in orbit?
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Falling at the same rate of environment
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How does your body sense which way is down?
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The fluid of your vestibular organs in your head.
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What use does math have instead of science?
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It is more precise.
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What are the steps in the scientific method?
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"1. Observe 2. Ask question 3. Hypothesize 4. Predict 5. Test prediction 6. Draw conclusion" |
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What are some branches of science?
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Chemistry, biology, geology, physics, etc. |
