PRAXIS II Physics Content Knowledge Exam Prep

Explanation
Johannes Kepler is the correct answer because he discovered the laws governing the motion of planetary bodies. Kepler's laws of planetary motion, published in the early 17th century, revolutionized our understanding of how planets move around the sun. His three laws describe the elliptical orbits of planets, the equal area law, and the relationship between a planet's orbital period and its distance from the sun. Kepler's discoveries laid the foundation for Isaac Newton's later work on gravity and motion.

Explanation
Galileo Galilei is the correct answer for the inventor of the telescope. Galileo Galilei was an Italian astronomer and physicist who is widely credited with inventing the telescope in the early 17th century. He made significant advancements in the field of astronomy by using his telescope to observe celestial bodies and challenging the geocentric model of the universe. Galileo's observations and discoveries laid the foundation for modern astronomy and revolutionized our understanding of the cosmos.

Explanation
Max Planck is associated with quantum mechanics. He is known for his work on the theory of quantum mechanics, specifically for introducing the concept of quantization of energy. Planck's discovery of energy quanta, or "packets" of energy, laid the foundation for the development of quantum theory. His contributions revolutionized our understanding of the behavior of particles at the atomic and subatomic levels.

Explanation
Quantum mechanics was pioneered by three physicists. This revolutionary theory was developed by Max Planck, who introduced the concept of quantized energy, Albert Einstein, who proposed the theory of the photoelectric effect, and Niels Bohr, who formulated the theory of atomic structure. Together, these three physicists made significant contributions to the field of quantum mechanics, leading to a fundamental shift in our understanding of the behavior of particles at the atomic and subatomic levels.

Explanation
The earth rotates or spins on its axis, causing day and night. This motion is known as rotational motion.

Explanation
Elasticity is not a kind of force because it is a property of materials that describes their ability to deform when subjected to an external force and return to their original shape when the force is removed. It is not a force itself, but rather a measure of how a material responds to a force. In contrast, impulse, momentum, and weight are all related to forces. Impulse is the change in momentum of an object, momentum is the product of an object's mass and velocity, and weight is the force exerted on an object due to gravity.

Explanation
Impulse is the time effect of force. When a force is applied to an object for a certain amount of time, it results in a change in momentum of the object. This change in momentum is known as impulse. Impulse is equal to the force applied multiplied by the time for which it acts. Therefore, impulse is the quantity that describes the time effect of force on an object.

Explanation
Weight is the correct answer because it is a measure of the force of gravity acting on an object. The Earth's pull, or gravity, causes objects to have weight. Weight is dependent on the mass of the object and the acceleration due to gravity. The greater the mass of an object, the greater its weight will be. Therefore, weight is a result of the Earth's pull on a body.

Explanation
Albert Einstein is credited with discovering the theory of relativity. His groundbreaking work in the early 20th century revolutionized our understanding of space, time, and gravity. The theory of relativity consists of two parts: the special theory of relativity, published in 1905, which deals with objects moving at constant speeds, and the general theory of relativity, published in 1915, which includes the effects of gravity. Einstein's theory of relativity has had a profound impact on physics and has been confirmed by numerous experiments and observations.

Explanation
Yuri Gagarin was the first man to land on the moon. He achieved this historic feat on April 12, 1961, when he became the first human to orbit the Earth aboard the Vostok 1 spacecraft. Gagarin's successful mission marked a significant milestone in space exploration and paved the way for future space missions, including the Apollo 11 mission that landed astronauts on the moon in 1969.