**that when a force is applied to move a body, it will continue to move indefinitely unless acted upon by an opposing force**.

What did Galileo not see?

**what did galileo observe**.

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Free Fall-Galileo Describes Motion Let us examine the results carefully. (a) First, he found that when a ball rolled down an incline at a fixed angle to the horizontal, **the ratio of the distance covered to the square of the corresponding time was always the same**.

Galileo discovered that a ball rolling down an in incline plane **picks up the same amount of speed in successive seconds, that is the ball rolls with unchanging acceleration – constant acceleration**. The gain per second is its acceleration. As the steepness of the incline increases, the acceleration also increases.

What was the greatest discovery by Galileo during his inclined-plane experiments? He discovered **that a ball rolling down an incline and onto a horizontal surface would roll indefinitely.**

According to the story, Galileo discovered through this experiment that **the objects fell with the same acceleration**, proving his prediction true, while at the same time disproving Aristotle’s theory of gravity (which states that objects fall at speed proportional to their mass).

Galileo’s thought experiment considered **rolling balls on inclined planes in the absence of friction or other resistant forces**. The speed acquired by a body moving down a plane from a height was sufficient to enable it to reach the same height when climbing up another plane at a different inclination .

Of all of his telescope discoveries, he is perhaps most known for his discovery of **the four most massive moons of Jupiter**, now known as the Galilean moons: Io, Ganymede, Europa and Callisto. When NASA sent a mission to Jupiter in the 1990s, it was called Galileo in honor of the famed astronomer.

Most falling objects move quickly. … The inclined plane thus **allowed Galileo to accurately measure acceleration with simple instruments** and ultimately to prove that, in the absence of other forces such as air resistance, gravity causes all falling objects to accelerate toward Earth at the same rate.

One of Galileo’s contributions to the founding of modern science was his study of falling objects. … He turned, then, to measuring the acceleration of **objects rolling down smooth ramps**. The ramp “diluted” the acceleration to a value small enough to allow accurate measurements of the longer time intervals.

Galileo Galilei—an Italian mathematician, scientist, and philosopher born in 1564—recognized that **in a vacuum**, all falling objects would accelerate at the same rate regardless of their size, shape, or mass. He arrived at that conclusion after extensive thought experiments and real-world investigations.

What is the net force on a cart that is pulled to the right with 100 pounds of force and to the left with 30 pounds of force? The net force is **70 pounds to the right**.

When **an object is in equilibrium** (either at rest or moving with constant velocity), the net force acting on it zero.

A | B |
---|---|

magnitude |
The _____ of a vector is always a positive quantity. |

origin | The center of a coordinate system is called the ____. |

Pythagorean relationship | The _____states that the sum of the squares of the two sides of a right triangle is equal to the square of the hypotenuse. |

Galileo accounted for the inertia of falling objects. So although the lead ball would be heavier than a wooden ball of the same size, it would also have more inertia. Since **it has more inertia, it resists changes in its state of motion**. … This is another reason for Galileo’s experimentation with inclined planes.

Galileo: What Aristotelian idea did Galileo discredit in his fabled Leaning Tower demonstration? He discredited **Aristotle’s idea that the rate at which bodies fall is proportional to their weight**.

Galileo’s laws of Motion: … determined that **the natural state of an object is rest or uniform motion**, i.e. objects always have a velocity, sometimes that velocity has a magnitude of zero = rest. objects resist change in motion, which is called inertia.

- Craters and mountains on the Moon. The Moon’s surface was not smooth and perfect as received wisdom had claimed but rough, with mountains and craters whose shadows changed with the position of the Sun. …
- The phases of Venus. …
- Jupiter’s moons. …
- The stars of the Milky Way. …
- The first pendulum clock.

After hearing about the “Danish perspective glass” in 1609, Galileo constructed his own telescope. He subsequently demonstrated the telescope in Venice. His demonstration of the telescope earned him a lifetime lectureship. After his initial success, Galileo focused on refining the instrument.

Describe Galileo’s experiments with inclined planes and state the conclusion. By observing the motion of objects on inclined planes, **Galileo deduced that objects move with constant speed when no force acts on them**. … He observed that when a marble rolls down an inclined plane, its velocity increases, as shown in Fig.

Galileo found that he could not measure motions of falling bodies directly, because **they accelerated too quickly**. Instead, he did experiments by rolling balls down inclined planes, so that the acceleration was much slower.

10. **In 1603**, Galileo performed a classic experiment in mechanics: he measured the distances covered by a ball rolling on an inclined plane, which slows down the ball, compared to its free fall.

Galileo decided to **study balls rolling (falling) down smooth inclined planes**. He reasoned that what is true for a gentle incline is true for a steeper incline and so on up to the steepest of all inclines – straight-down free fall.

Galileo’s experimental apparatus was simple; it consisted of a **wooden ramp with a groove cut into it and a bronze ball**. The bronze ball would roll down the groove, and he could track its motion due to gravity.

Galileo determined **the laws of gravity and explored the laws of motion on earth**. Newton first conclusively affirmed the laws of motion and linked them with Kepler’s laws of planetary motion.

Galileo’s law of free fall states that, **in the absence of air resistance, all bodies fall with the same acceleration, independent of their mass**.

When you jump vertically off the ground, what is your acceleration when you reach your highest point? Discuss this in light of Newton’s second law. When you get to the highest point **a=10m/s^2 and net force=0.**

What did Copernicus say about the motion of the Sun? **The Sun is stationary and Earth circles it**. … Newton refined Galileo’s concept of inertia and made it his first law of motion.

Why do the alphabet letters tend to do what they do when you rotate the bowl? **They have inertia**−the tendency of an object at rest to stay at rest. The letters are heavier than the soup, so they cannot move even though the soup moves. The sides of the soup bowl prevent the letters from moving.

Why might your foot hurt if you kick a heavy desk or a wall? When you kick a heavy desk or a wall, **your foot exerts a force on the desk or wall**. The desk or wall exerts a force equal in magnitude on your foot (Newton’s third law). Ouch!

Free body diagrams are **used to visualize forces and moments applied to a body and to calculate reactions in mechanics problems**. These diagrams are frequently used both to determine the loading of individual structural components and to calculate internal forces within a structure.

Acceleration is the change of velocity per unit time, so if there is no force, all we know is that the acceleration is zero. Therefore, the velocity is not changing. If the object was already moving, then it will just keep moving. So, **yes, the object can be moving when there is no force applied** to it.

Answer: Magnitude cannot be negative. … The zero vector (**vector where all values are 0**) has a magnitude of 0, but all other vectors have a positive magnitude.

Distance traveled is the total length of the path traveled between two positions. Distance traveled is not a vector. **It has no direction** and, thus, no negative sign.

Speed is the absolute value of the velocity or the magnitude of the velocity. **Speed is always positive**. To tell whether an object is moving to the right or to the left, if you use “speed” you must also specify the direction.

Galileo’s Law of Inertia states that; **if no net force acts on an object, the object maintains in the same state of motion**. This is a restatement of Newton’s First Law of Motion. The first law of Motion is also known as Galileo’s law of inertia.

His first biographer, Vincenzo Viviani, states that he began his study of pendulums **after he watched a suspended lamp swing back and forth in the cathedral of Pisa when he was still a student there**. Galileo’s first notes on the subject date from 1588, but he did not begin serious investigations until 1602.

The Difference between Aristotle’s concept of motion and Galileo’s notion of motion is **eleven o’clock That aristotle Affirmed That force is removed from an object it will stop while Galileo said an objects motion is stopped Because of the force of friction**.