Final Exam Review

Question 1

What is Kepler’s First Law?

Answer 1

All planets in the solar system have elliptical orbits wit the sun at one focus.

Question 2

What is Kepler’s Second Law?

Answer 2

(The Law of Equal Areas):An imaginary line drawn from the centre of the sun to centre off the planet will sweep out equal areas in equal intervals of time.

Question 3

What is Kepler’s Third Law?

Answer 3

The ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the star

Question 4

What is Newton’s Second Law of Motion?

Answer 4

Non-zero net force will accelerate an object.

Question 5

If an object is moving with constant velocity does it have an acceleration or Fnet?

Answer 5

No, if acceleration is equal to zero then Fnet must be equal to zero.

Question 6

What is Newton’s Third Law of Motion?

Answer 6

For every action there is an equal and opposite reaction. It is important to note action and reaction forces occur on different objects, NOT the same one.

Question 7

What is the Work-Energy Theorem?

Answer 7

The net work done on an objet equals the objects change in kinetic energy.

Question 8

What are conservative forces?

Answer 8

Naturally occurring force like the force of gravity.

Question 9

What are non conservative forces?

Answer 9

Energy that is not stored as potential energy/

Question 10

What is the conservation of mechanical energy?

Answer 10

The mechanical energy is the sum of the kinetic and potential energies.

Question 11

What is static friction?

Answer 11

Friction that prevents motions.

Question 12

What is kinetic friction?

Answer 12

Friction that occurs during motion

Question 13

How does Newton’s Law of Universal Gravitation relate to Kepler’s Laws?

Answer 13

Fc = Fg

Question 14

Where does the instantaneous velocity act?

Answer 14

Is always tangent to the circle.

Question 15

What is the formula of Kepler’s Third Law?

Answer 15

Ta^2/Ra^3 = Tb^2/Rb^3

Question 16

Where does the instantaneous velocity act in UCM?

Answer 16

Is always tangent to the circle.

Question 17

What is Newton’s Law of Universal Gravitation?

Answer 17

Newton thought of his law when he saw an apple fall out of a tree. Using F = ma the force of gravity must be proportional to the mass. Applying Newton’s Third Law there must be an equal and opposite force on Earth.

Question 18

What are satellites?

Answer 18

• An object in orbit around another mass where only the force of gravity acts.
• Most satellites are in circular orbit.
• They moves at a constant speed therefore they are in UCM.
• To calculate use: Fc = Fg

Question 19

What are geostationary satellites?

Answer 19

Satellites that appear to be stationary to the observer but they move at high velocities.

Question 20

What is the orbital period for geostationary satellites?

Answer 20

24 hours.

Question 21

What are scalar fields?

Answer 21

A scalar field associates a scalar value to every point in space. Scalar fields are often used to indicate the temperature disturbance, air pressure, sound intensity and light intensity.

Question 22

What are vector fields?

Answer 22

A vector field associates a vector to every point in space. Common examples include magnetic field and gravitational fields.

Question 23

What is work?

Answer 23

If a constant force is applied to an object over a distance, then the work done by that force is given by W= Fdcos0.
Work is a scalar quantity.