Physics Quiz (Unit 4 Quiz 1)

Newton’s First Law

An object at rest remains at rest and an object in motion remains in motion with the same speed and direction as long as the forces remain balanced. If the net force is zero, the velocity will remain constant.

Newton’s Second Law

The acceleration of an object is directly proportional to the net force acting on the object and inversely proportional to mass of the object

Newton’s Third Law

For every force that acts on an object, there is a reaction force acting on a different object that is equal in magnitude and opposite in direction.

Law of Inertia

Newton’s first law of motion is also known as the Law of Inertia.

Law of action/reaction

Newton’s Third Law of Motion, also known as the Law of Action/Reaction states:

Force

 is sometimes defined as a push or a pull on an object. More specifically, a force is the ability to cause a change in state of motion of an object.

Mass

of an object, as you likely learned in the past, is a measure of the quantity of matter in the object.

Inertia

is a fundamental property of matter that causes it to resist changes in its state of motion.

This “change to a state of motion” means a change in velocity.

Action Force

Thing that applied the force

Reaction Force

Thing that exerts the forces back onto the thing that applied the forces onto it.

Balanced Forces

when the forces on an object sum up to zero.

Unbalanced Forces

when the forces on an object do not sum up to zero.

Contact Forces

 are the result of two objects touching each other. Friction, normal force, spring force and tension act at a distance - objects do not need to touch each other.

Field Forces

 act at a distance - objects do not need to touch each other. Examples of field forces include gravitational force and magnetic and electric forces.

Net Froce

vector sum of all the forces that act upon an object.

Friction

 force that resists relative motion between two surfaces in contact.

Tension

 is defined as the force transmitted through a rope, string or wire when pulled by forces acting from opposite sides. The tension force is directed over the length of the wire and pulls equally on the bodies at the ends.

𝚺 what this symbol means

"Sigma" and is used in mathematics to represent summation, meaning "add up" - it signifies the sum of a series of terms;

𝚫 what this symbol means

"change" or "difference" between two values

Normal Force

 a force that points perpendicular to a solid surface such as a table, wall, ground etc. The force is always perpendicular to the surface an object is resting on. 

Weight

The weight, F_g, of an object on the Earth’s surface is the gravitational force exerted on the object by the Earth. 

newton (the unit)

1 Kg m/s ²

coefficient of static friction

Fs max = Ms Fn and Ms is coefficient. a measure of how much force is needed to initiate movement between two surfaces that are currently at rest,

Coefficient of kinetic friction

Fk = Mk Fn. represents the ratio of the force of kinetic friction acting on a moving object to the normal force exerted on that object by a surface, essentially measuring how much friction exists between two surfaces when an object is sliding across

Spring Constant

you would find that the stretch of the spring is proportional to the weight hanging on the end of the spring. 

The constant of proportionality is called the spring constant, k. 

Writing this as an equation, we can say that 

Fsp = -k𝛥x

Kinetic Friciton

experienced by surfaces that are in contact AND moving relative to one another. 

Spring Force

a restoring forced exerted by a spring when it is stretched or compressed.

static friction

 between two surfaces that are in contact with each other but NOT moving.