QCM : Fundamentals of Planar and Circular Motion — 8 questions

Explication

The fundamental feature of planar motion is that all points of the moving object stay within a single plane, which simplifies the analysis of its movement. This key characteristic distinguishes it from spatial (three-dimensional) motion.

Explication

Rotation is a planar movement where a body turns about a fixed point or axis, with all points moving along circular paths around that point. Translation involves linear movement without changing orientation, and general plane motion combines translation and rotation.

Explication

The concept of kinematic quantities was first formalized and extensively discussed during the scientific revolution, particularly through Galileo's work in the early 17th century, roughly between 1600 and 1650, making the first option the correct answer.

Explication

The difference in the velocities of two objects causes the observed relative motion, as the relative velocity is defined by subtracting their velocity vectors. This difference determines how one object appears to move from the other's frame, making it the primary cause of relative motion effects.

Explication

Isaac Newton is credited with formulating the laws of motion and universal gravitation, which provide the fundamental framework for understanding forces in circular motion, especially centripetal force. Galileo contributed to early studies of motion but did not formulate the specific laws governing circular motion. Einstein revolutionized physics with relativity but did not focus on classical circular motion. Faraday is known for electromagnetism, not mechanics.

Explication

Galileo began his investigations into motion and the principles of mechanics around 1604, which contributed significantly to the understanding of uniform motion. This period marks the start of his work that challenged Aristotelian views and laid the groundwork for classical mechanics.

Explication

In projectile motion, the horizontal component of velocity remains constant because there is no acceleration in the horizontal direction (assuming no air resistance). The vertical component, however, is affected by gravity, which causes a constant acceleration downward. Therefore, the key difference is that the horizontal component has constant velocity, while the vertical component accelerates under gravity.

Explication

The velocity of the boat relative to the riverbank is obtained by vectorially adding the boat's velocity relative to water (east) and the water's velocity relative to the bank (north). This results in a velocity of approximately 15 m/s directed northeast, which combines the eastward and northward components.