Grade 9 Physiscs Midterm Exam Review Guide

First rule of significant figures

All non-zero numbers are significant

Second rule of significant figures

Zeroes between two non zero digits are significant

Third rule of significant figures

Leading zeroes are not significant

Fourth rule of significant figures

Zeros after the significant figures and after the decimal place are significant

What is the rule for significant figures in multiplication?

For multiplication, round the final answer to the same number of significant figures as the measurement with the least number of significant figures.

What is the rule for significant figures in division?

For division, round the final answer to the same number of significant figures as the measurement with the least number of significant figures.

What is the rule for significant figures in addition and subtraction?

For addition and subtraction, round your final answer to the same number of decimal places as the measurement with the fewest decimal places (the "least precise" number), not the total significant figures

What is Percision?

How close you can consistently achieve a desired result

What is Accuracy?

How close you can come to a specific result

What is displacement?

The change in an objects position relative to its starting point

What is distance?

The overall length covered by an object

What is velocity?

a vector quantity measuring speed and direction

What is speed?

a scalar quantity measuring how fast something is going in a specific direction

What is acceleration?

the change in velocity of an object over time

What is negative acceleration?

How fast an object slows down

What is positive acceleration?

How fast an object's velocity increases over time

How do you calculate slope?

Rise over run (rise/run)

What kind of motion does zero slope represent?

zero motion, at rest

What kind of motion does a positive slope represent?

Positive acceleration

What kind of motion does negative slope represent?

Slowing down/moving in opposite direction

On a position vs. time graph, what does slope represent?

Velocity

On a velocity vs. time graph, what does slope represent?

Acceleration

What is freefall?

When an object is only acted upon by gravitational force

When you throw an object in the air, what pulls it back down?

Gravity

What is the acceleration due to gravitational force?

-9.8m/s²

Is freefall symmetrical?

Yes, it will take the same time for the object to fall as it does to rise

What is a projectile?

An object moving through the air after being acted upon by a force

What is the difference between horizontal projectile motion and freefall?

In freefall gravity is the only force acting on the object, in horizontal projectile motion, there is horizontal force on the object

Can time ever be negative?

No

Is time different in the x-direction than in the y-direction?

No, time remains the same

SOH

Sin=Opposite/Hypotenuse

CAH

Cos=Adjacent/Hypotenuse

TOA

Tan=Opposite/Adjacent

How does SOHCATOA apply to angled motion and velocity?

It can be used to find the length of different angles that an object moves at.

What is inertia?

the resistance an object has to unbalanced forces

What is Newtons first law?

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.

Does an object with more mass have more inertia?

Yes

What is mass?

the amount of matter in an object

What is weight?

A measure of the force of gravity on an object

How are Newton's first law and inertia related?

An object with more mass will be harder to be acted upon by unbalanced forces

What is weight/Gravitational force?

A force that moves objects downward toward the ground

What is tension?

The force within a stretched object such as a cable or rope.

When does tension occur?

When a force pulls on an object such as a rope, cable or pulley

What is the difference between static and kinetic friction?

Static friction affects non-moving objects, while kinetic friction approves moving objects

What is normal force?

The upward force of the ground.

Why is it called "normal force"?

Because it acts perpendicular to the object its affecting

When does normal force occur?

When an object is sitting on the ground or another surface

Is normal force always present?

No, it only occurs when to objects are pushing against each other

What is Newton's 2nd Law?

F=ma (force = mass x acceleration)

What is net force?

The combination of all forces acting on an object

Can an object be moving if there is no net force acting on it?

Yes, an object can be moving.