Physics Flashcards

The rate at which a vehicle's velocity changes over time?

Answer: Acceleration

Acceleration is defined as the rate at which an object's velocity changes over time. Velocity includes both speed and direction, so acceleration can involve a change in speed, a change in direction, or both. It is a vector quantity, meaning it has both magnitude and direction.

Unless operated on by an imbalanced force, the body at rest will remain at rest, and the body in motion will remain in motion with a constant velocity; F=ka

Answer: Newton's First Law of Motion

This statement is a direct description of Newton's First Law of Motion, also known as the Law of Inertia. It states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. The formula F=ka is not part of Newton's First Law, which primarily describes inertia.

A push or a pull on an item is defined as _________.

Answer: Force

Force is defined as a push or a pull that can cause an object to accelerate, change its velocity, or deform. It is a vector quantity, possessing both magnitude and direction. Forces are fundamental to understanding motion and interactions in physics.

It is possible for an object to show two different types of motion at the same time.

Answer: Project Motion

Projectile motion is a classic example where an object exhibits two types of motion simultaneously: constant horizontal velocity (ignoring air resistance) and vertical acceleration due due to gravity. This combination of independent horizontal and vertical movements allows an object to follow a parabolic path, demonstrating two distinct motions at once.

Which of the following is true regarding the way light travels?

Answer: Light travels as both a wave and a particle

Light exhibits wave-particle duality, meaning it behaves as both a wave and a particle. It demonstrates wave-like properties such as diffraction and interference, while also acting as discrete packets of energy called photons, which are particles. This dual nature is a fundamental concept in quantum physics.

According to the theory of the same name, after the “Big Bang” there were only what two things?

Answer: Matter and antimatter

According to the Big Bang theory, in the extremely hot and dense conditions of the early universe, energy was converted into pairs of matter and antimatter particles. While most of these annihilated each other, a slight imbalance led to a small excess of matter, which eventually formed all the structures we observe today.

A subatomic particle is which of the following in relation to an atom?

Answer: Smaller

A subatomic particle is, by definition, any particle that is smaller than an atom. Atoms are composed of these fundamental particles, such as protons, neutrons, and electrons. Therefore, these constituent parts are inherently smaller than the complete atom.

Who discovered the special theory of relativity?

Answer: Albert Einstein

Albert Einstein is credited with developing the special theory of relativity, which he published in 1905. This revolutionary theory established that the laws of physics are the same for all non-accelerating observers and that the speed of light in a vacuum is constant for everyone.

A fresh egg will float in water…

Answer: When salt is added to the water

An object floats when its density is less than the density of the fluid it displaces. Adding salt to water increases the water's density. If enough salt is dissolved, the saltwater solution becomes denser than the egg, causing the egg to float.

How fast does sound travel through a vacuum?

Answer: 0 m/s

Sound is a mechanical wave, meaning it requires a medium (like air, water, or solids) to transmit its vibrations. A vacuum is a space devoid of matter, so there are no particles to vibrate and carry the sound waves. Therefore, sound cannot travel through a vacuum, resulting in a speed of 0 m/s.

What planet is the slowest rotating and often referred to as Earth’s “sister planet?”

Answer: Venus

Venus has the slowest rotation period of any planet in our solar system, taking longer to rotate once on its axis than to orbit the Sun. It is often called Earth's 'sister planet' due to its similar size, mass, and overall composition, despite its extremely hostile surface environment.

A woman has a mass of 50 kg on the moon. What is her mass on Earth?

Answer: 50 kg

Mass is a fundamental measure of the amount of matter in an object and is an intrinsic property that remains constant regardless of location or gravitational pull. While an object's weight changes with gravity (e.g., less on the Moon), its mass of 50 kg will be the same on Earth as it is on the Moon.

A ball is at the top of a hill. Which factor, or factors, is responsible for its potential energy?

Answer: Its position and its mass

Gravitational potential energy (PE) is determined by an object's mass (m), its height or position (h) relative to a reference point, and the acceleration due to gravity (g). The formula PE = mgh clearly shows that both the object's mass and its vertical position are directly responsible for its potential energy.

Which of the following is true of a negatively charged particle?

Answer: It has more electrons than protons

A particle becomes negatively charged when it gains electrons, which carry a negative charge. This creates an imbalance where the number of negatively charged electrons exceeds the number of positively charged protons within the particle. Conversely, a positive charge indicates a deficit of electrons.

At a speed of 8 m/s, a 0.5 kg object suspended from a 0.75 m rope circles a center point. How much stress does the string feel in the absence of gravity?

Answer: 42.7 N

In the absence of gravity, the stress on the string is entirely due to the centripetal force required to keep the object moving in a circle. The centripetal force (Fc) is calculated using the formula Fc = mv²/r, where m = 0.5 kg, v = 8 m/s, and r = 0.75 m. Plugging in these values gives Fc = (0.5 * 8²) / 0.75 = 32 / 0.75 ≈ 42.67 N.

A baseball weighs 0.145 kg. It needs to be thrown at what speed to have a kinetic energy of 57 J?

Answer: 28.0 m/s

Kinetic energy (KE) is calculated using the formula KE = ½mv², where m is mass and v is velocity. To find the velocity, we rearrange the formula to v = √((2 * KE) / m). Plugging in the given values: v = √((2 * 57 J) / 0.145 kg) = √(114 / 0.145) = √(786.2) ≈ 28.04 m/s.