Physics Lecture - Projectile Motion and Orbits

These flashcards cover key concepts related to projectile motion and orbital mechanics discussed in the physics lecture.

What happens to the horizontal component of velocity of a stone thrown upward at an angle as it rises?

It remains constant if air resistance is ignored.

What happens to the horizontal component of velocity of a stone thrown upward at an angle as it falls?

It remains constant if air resistance is ignored.

A projectile falls beneath the straight line path it would follow without gravity. How far does it fall after 1 second?

4.9 meters.

How far does a projectile fall below its straight line path after 2 seconds?

19.6 meters.

If a projectile is launched vertically at 100 m/s, at what speed will it return to its initial level, ignoring air resistance?

100 m/s.

Why doesn't the force of gravity change the speed of a satellite in circular orbit?

The gravitational force acts as a centripetal force, continuously changing the direction of the satellite without changing its speed.

At what part of an elliptical orbit does an Earth satellite have the greatest speed?

At perigee.

At what part of an elliptical orbit does an Earth satellite have the lowest speed?

At apogee.

What did Kepler discover about the periods of planets and their distances from the Sun?

Kepler's Third Law states that the square of the period of a planet is proportional to the cube of its average distance from the Sun.

Is the sum of kinetic and potential energies a constant for satellites in circular or elliptical orbits?

Yes, it is a constant.