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Grade 7 Newton’s Laws and Motion Review Study Guide
Grade 7 Newton’s Laws and Motion
Review Study Guide
Name: ________
Date: ____
Class: ____
Directions
Complete each section using your notes, textbook, or class activities. Then use the practice questions to check your understanding.
Motion Vocabulary
Motion
Motion is a change in an object's ____ compared with a ____ point.
Speed
Speed describes how ____ an object moves.
Formula:
Time
Time tells how long an object moves.
Formula:
The usual unit for time is seconds (s).
Example: A cyclist travels 60 meters at 12 m/s.
Time = ____ s
The usual units for speed are ____.
Example: A runner travels 100 meters in 20 seconds.
Speed = ____
Velocity
Velocity is speed in a specific ______.
Example: The car travels 20 m/s ____.
How is velocity different from speed?
______________
______________
Distance
Distance is the total ____ traveled by an object.
Distance is a ____ quantity because it has no direction.
Displacement
Displacement is the ____ distance and direction from an object's starting point to its ending point.
Example: You walk 5 meters east and then 5 meters west.
Distance = ____
Displacement = ____
Scalars and Vectors
Scalar
A scalar has ____ only.
Examples of scalar quantities: __________
Vector
A vector has both ____ and ____.
Examples of vector quantities: __________
Circle the vector quantities:
25 m
25 m north
10 m/s
10 m/s west
50 seconds
50 N to the right
Explain why direction matters for a vector:
______________
Force
A force is a ____ or a ____ that can change an object's motion.
The unit of force is the ____, abbreviated __.
A force can cause an object to:
______________
______________
______________
______________
Balanced Forces
Balanced forces are equal in size and opposite in ____. The net force is __ N, so the object's motion ____ change.
Unbalanced Forces
Unbalanced forces produce a net force that is not _ N. They can change an object's ___, ___, or _____.
A box has a 12 N push to the right and a 7 N push to the left.
Net force = ____ N to the ____.
Are the forces balanced or unbalanced? ____
Force and Acceleration
Acceleration is a change in ____ over time.
Acceleration can mean:
speeding up
____
changing ____
Calculating Acceleration
What is the formula for acceleration?
\(a\) = acceleration, in m/s²
\(t\) = time, in seconds
To calculate acceleration, subtract the initial velocity from the final velocity, then divide by time.
Example: A car speeds up from 4 m/s to 16 m/s in 6 seconds.
Acceleration = ____ m/s²
Practice: A skateboarder changes velocity from 2 m/s to 14 m/s in 4 seconds.
Acceleration = ____ m/s²
Newton's Second Law is written as:
In this equation and show units please:
(F) = ____
(m) = ____
(a) = ____
If the net force increases while mass stays the same, acceleration ____.
If mass increases while force stays the same, acceleration ____.
Practice: A 4 kg cart is pushed with a net force of 20 N.
Acceleration = ____
Practice: A 5 kg object accelerates at 3 m/s², what is the force?
Net force = ____
Inertia
Inertia is an object's tendency to resist a change in its ____.
An object's inertia depends on its ____.
More mass means ____ inertia.
Example: When a car stops suddenly, passengers move forward because their bodies tend to keep moving. This is an example of ____.
Which has more inertia: a bowling ball or a tennis ball? ____
Why? ______________
Newton's First Law
Newton's First Law is also called the Law of ____.
An object at rest tends to stay at ____, and an object in motion tends to stay in ___ with the same speed and direction unless acted on by an _____ force.
This law explains why objects with more inertia are ____ to start moving or stop moving.
Real-life example:
______________
______________
Newton's Second Law
Newton's Second Law explains the relationship among force, mass, and ____.
The formula is \(F = ma\).
A greater force produces a ____ acceleration if mass stays the same.
A greater mass produces a ____ acceleration if force stays the same.
Real-life example:
______________
______________
Newton's Third Law
Newton's Third Law states that for every action force, there is an equal and ____ reaction force.
The action and reaction forces act on ____ objects.
Example: When you push on a wall, the wall pushes back on you with an equal force.
Write another example of Newton's Third Law:
______________
______________
In a swimming motion, a swimmer pushes water ____, and the water pushes the swimmer ____.
Review and Apply
A soccer ball is sitting still. What must happen for it to begin moving?
______________
Why does a heavier object usually require more force to accelerate at the same rate as a lighter object?
______________
A bicycle changes from moving east to moving north at the same speed. Is it accelerating? Explain.
______________
A student walks 8 m north and then 3 m south.
Total distance = ____
Displacement = ____
A 10 kg cart experiences a net force of 50 N. What is its acceleration?
______________
Identify the law shown: A rocket pushes gases downward, and the gases push the rocket upward.
Newton's Law: ____
Identify the law shown: A passenger moves forward when a bus stops suddenly.
Newton's Law: ____
Identify the law shown: An empty shopping cart accelerates more than a full cart when both receive the same push.
Newton's Law: ____
Quick Check Before the Quiz
Write one sentence explaining each idea.
Inertia:
______________
Force:
______________
Acceleration:
______________
Velocity:
______________
Distance:
______________
Displacement:
______________
Scalar:
______________
Vector:
______________
Newton's First Law:
______________
Newton's Second Law:
______________
Newton's Third Law:
______________
Final Memory Check
Complete these from memory:
Speed = ____ ÷ ____
Force = ____ × ____
velocity = ____ ÷ ____
Time = ____ ÷ ____
Force = ____ × ____
Acceleration = (____ − ___) ÷ _____
In the acceleration formula, (vf) means ___ velocity and (vi) means ____ velocity.
Newton's First Law = Law of ____
Every action has an equal and ____ reaction.
A vector includes ____ and ____.
Displacement includes the object's change in ____ and ____.