Natalie, Isabella, Roberto Flashcards
Vocabulary: What is Energy?
The ability to do work
What is Gravity?
A force that attracts all objects toward each other.
What is kinetic energy?
A form of energy that an object or a particle has by reason of its motion.
Example of kinetic energy: A moving car
Definition of work
Measure of energy transfer that occurs when an object is moved over a distance by an external force
What is the 1st Kepler’s Law?
Every planet’s orbit is an ellipse with the Sun at a focus
What is Kepler’s 2nd Law?
A line joining the Sun and a planet sweeps out equal areas in equal times
What is Kepler’s 3rd Law?
The square of a planet’s orbital period is proportional to the cube of the semi-major axis of its orbit.
A person throws a pumpkin at a horizontal speed of 4.0 m/s off a cliff. The pumpkin travels 9.5m horizontally before it hits the ground.
Find the vertical displacement.
The pumpkin’s vertical displacement is H=27.76m
What is an ellipsis?
It is a closed, curved shape which has two foci. The distance between the two foci is proportional to it’s eccentricity.
Compare the ‘g’ value experienced by a 100kg elephant and a 1g fly, which both stand on the earth’s crust side-by-side.
The ‘g’ value is the same- g is independent of mass other than that of the central, larger mass (M)
What direction of rotation is the Earth?
West to East
What is inertia?
The resistance of any physical object to any change in its velocity.
What is an Angular displacement?
The change in the angle as an object rotates
A player kicks a football from ground level with an initial velocity of 27.0 m/s, 30.0° above the
2.8 s
What is the formula for momentum?
p = mv
A rock is thrown horizontally from a cliff at 25 m/s.
What will its horizontal and vertical velocities be after 2.0 s?
a) horizontal: 25.0 m/s, vertical: -19.6 m/s
Formula for kinetic energy
K.E. = 1/2 m v2
If mass stays the same
and distance increases
then the force of gravity…
decreases
What is the Law of Conservation of Energy?
Energy may change form, but it cannot be created or destroyed under ordinary conditions
What two factors keep the plants in orbit?
inertia and gravity
Equation for work
w(ork) = f(orce) x d(istance)
How does newtons first law of universal graviton apply to earth and the moon?
Earth pulls on the moon and every object attracts another object
Equation for power
p(ower) = w(ork) / t(ime)
How does distance affect the strength of the force of gravity?
The bigger the distance the weaker the gravitational pull
What is the law of universal graviton?
States every object in the universe attracts every other object
