4weekExam2ndnineweeks_review

 

 

The idea that we live in a universe (literally, "one story"), in which the same law of gravity applies both on Earth and in space, was established through the work of _________

• Copernicus.

• Galileo.

• Newton.

• Kepler.

Which person realized the laws of gravity applied to objects both on Earth and in space?

• Copernicus

• Newton

• Galileo

• Kepler

Two bowling balls with different masses are dropped from the same height. How do their accelerations compare?

• They both fall with the same acceleration.

• The lighter bowling ball accelerates faster.

• The heavier bowling ball accelerates faster.

If a net force is applied to an object, what is guaranteed to change?

• the object's direction of motion

• the object's weight

• the object's speed

• the object's momentum

• the object's mass

According to Einstein's equation, E = mc2, which of the following statements is true?

• One kilogram of mass represents 1 joule of energy.

• It takes a large amount of mass to produce a small amount of energy.

• A small amount of mass can be turned into a large amount of energy.

• Mass can be turned into energy, but energy cannot be turned back into mass.

• Mass can be turned into energy if it is accelerated to the speed of light.

In the formula E = mc2, what does E represent?

• the radiative energy carried by light

• the kinetic energy of a moving object

• the electric charge of the object

• the mass-energy or potential energy stored in an object's mass

• the gravitational potential energy of an object held above the ground

Gasoline can be used to power cars because it has

• electrical potential energy.

• radiative energy.

• kinetic energy.

• gravitational potential energy.

• chemical potential energy.

Consider Newton's second law states, often written as force = mass × acceleration. If a known force is applied to an object with a known mass, what does this law predict for the object's acceleration?

• acceleration = mass / force

• acceleration = mass × force

• acceleration = force / mass

• Newton's second law is irrelevant for solving this problem.

Based on fundamental laws of motion and gravity, which of the following best explains why Kepler's second law (planets move faster in the parts of their orbit that are closer to the Sun and slower when they are farther from the Sun) is true?

• The gravitational influence of other planets determines the speed of any particular planet's orbit.

• A planet's angular momentum must be conserved as it moves around its orbit.

• The strength of gravity is inversely proportional to the square of the distance between two objects.

• The speed of a planet at any point in its orbit depends on its temperature, which varies with distance from the Sun.

As an interstellar gas cloud shrinks in size, the law of conservation of angular momentum predicts it will

• heat up.

• rotate faster.

• slow down in its rotation.

• continue shrinking.

• cool off.