Physics Principles and Concepts: Key Definitions

Posted on Mar 4, 2025 in Physics

Key Definitions and Principles in Physics

Acceleration is defined as the change in velocity divided by the time interval.
It’s more difficult to start moving a heavy carton from rest than it is to keep pushing it with constant velocity because μ_s > μ_k.
The number of complete vibrations per second is the frequency.
Suppose an object is in free fall. Each second, the object falls a greater distance than in the second before.
When an object is thrown vertically upward, neglecting air resistance, its travel time upward is the same as its travel time downward.
A cyclist finishes a 100 km race in 2.7 hours. The average velocity equals the displacement divided by the total time.
A truck (big mass) and a compact car (small mass) travels with the same kinetic energy. It is possible if the speed of the truck is the smallest.

According to Pascal’s principle, any change on a confined fluid is transmitted unchanged throughout the fluid.
The SI unit of pressure is the Pascal.
The buoyant force exerted on an object immersed in a fluid is equal to the weight of the displaced fluid.
Pressure can be calculated as force divided by area.
Pressure in a liquid depends on the density of the liquid and the depth of the measuring point.

Turning up the flame under a pan of boiling water causes the water to boil away faster.
A chunk of ice (T = -20 ºC) is added to a thermally insulated container of cold water (T=0°C). What happens in the container? Some of the water freezes and the chunk of ice gets larger.
A temperature change of 20 °C corresponds to a temperature change of 36 °F.

A negative ion has more electrons than protons.
The force of attraction or repulsion between two charged particles is described by Coulomb’s Law (None of the provided options).
A volt is a unit of electrical potential.
When resistors are connected in parallel with each other, we can be certain that the potential difference across each is the same.
An important difference between insulators and conductors is that in conductors: charges can move freely, the electric field inside is zero, and the potential is constant.
The force on a test charge in an electric field is directly proportional to the magnitude of the field.
The electric current is the rate at which charge passes through a conductor.
When resistors are connected in series, the current flowing in each is the same.
A positive ion has more protons than electrons.
The difference between an electric field and field lines is that field lines are only a model of an electric field.
Potential (“Voltage”) is the energy a charged object has because of its position.
When resistors are connected in parallel with each other, we can be certain that the potential difference across each is the same.

In which of the following situations is no work done on a ball? Carrying the ball along the field.
You throw a ball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down. Work up is negative, and the work down is positive.