Physical Science - Force and Motion (8th Grade)

Force and Motion quiz on Wednesday

What is a vector?

It has both magnitude and direction, represented by an arrow. Examples include velocity, acceleration, momentum, and force.

What is a scalar?

It only has magnitude and no direction. Examples include speed, energy, power, temperature, and mass.

What does Newton's First Law state?

An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an external force. This tendency to resist changes in motion is called inertia.

What is inertia?

The tendency of an object to resist changes in its state of motion. The greater the mass, the greater the inertia.

What does Newton's Second Law state?

The acceleration of an object is dependent upon the net force acting upon it and the mass of the object.

What does Newton's Third Law state?

For every action (force) in nature, there is an equal and opposite reaction. Forces result from interactions between objects.

What is a force?

A push or pull on an object, which can cause changes in speed or direction of motion.

What is Newton's universal law of gravitation?

It states that the force of gravity affects all objects with mass in the universe. Greater mass results in a stronger gravitational force, and closer objects experience a stronger gravitational attraction.

What are the four types of friction?

Static, sliding, rolling, and fluid friction. Static friction is the strongest, followed by sliding, rolling, and fluid friction.

What is momentum?

Defined as 'mass in motion.' It is calculated as the product of an object's mass and its velocity

What is the formula for work?

The use of force to move an object a certain distance, calculated as Work = Force × Distance. The SI unit for Work is Joules.

What is power in physics?

It measures the amount of work done over time, calculated as (Word) = Work / Time. The SI unit for (word) is the Watt, which equals one joule per second.

How does Newton's First Law apply to a tablecloth being pulled quickly?

The dishes remain still because of inertia, as long as the friction from the movement of the tablecloth is not too great.

How does Newton's Second Law apply when kicking a ball?

The stronger the ball is kicked, the stronger the force applied, resulting in greater acceleration and distance traveled.

How does Newton's Third Law apply to a bird flying?

The wings of the bird push air downwards (action force), and the air pushes the bird upwards (reaction force).

The SI unit for force

The Newton (N).

Formula and unit for momentum

(p = mass × velocity), with the unit kg*m/s.

Formula and unit for power

(Word) = Work / Time. The SI unit for power is the Watt, which equals one joule per second.