Forces
What is a force?
a push or pull
What is inertia?
tendency of an object to resist change in movement
Which type of force will cause a change in motion?
a. balanced force
b. unbalanced force
What is acceleration? Give an example.
a CHANGE in speed and/or direction. Train slowing down; horse speeding up
What is NET FORCE?
TOTAL FORCE
What is friction? Is it a contact or non-contact force?
when two materials rub against each other. contact force because it's TOUCHING
What is Newton's First Law of Motion? HINT: also called the Law of Inertia
An object in motion stays in motion. An object at rest stays at rest.
Draw an example of a BALANCED FORCE. Give net force.
Net force = 0 Newtons
What is motion? Give an example.
smallest - farther away object is from light source
What is gravity? contact or non-contact?
Newton's 2nd Law of Motion states that _____.
Force = Mass x Acceleration
the bigger the mass, the greater the force needed to move it
Draw an example of an UNBALANCED FORCE. Use arrows and label net force.
movement in a direction.
What is a Newton?
what is a shadow?
an area of partial darkness when light is blocked by an object
What are the two main types of friction? Explain what they do.
Air Resistance - air rubs against object and pushes UP as gravity pulls DOWN
Water Resistance - water pushes UP as gravity pulls DOWN.
Give one example of Newton's Third Law of Motion.
3rd Law - For every action, there is an equal and opposite reaction.
push on wall, it pushes back with same amount of force
Johnny was helping his friend push a box that requires 300 N to move. Johnny pushes with 125 Newtons of force. How much force will his friend need to move the box? Draw a picture to help.
175 Newtons
What is uniform motion? Give one example.
motion where speed and direction do NOT change. an object at rest = example
which time of day is your shadow the SHORTEST? Why?
NOON because the sun is right above you.
What are three types of non-contact forces? Give one example of each.
magnetic forces - magnets pulling metal stuff to it
electric forces - static balloon; electricity
gravity - something falling
Give me an example where all THREE of Newton's Laws of Motion are in effect
1st law - an object in motion stays in motion. An object at rest stays at rest.
2nd law - force = mass x acceleration
3rd law - for every action, there is an equal and opposite reaction.
How much force is needed to move a 50 kilogram box with an acceleration of 9 meters per second?
450 Newtons
What is the difference between mass and weight? What term do we use to describe the force of gravity on an object?
mass = how much matter
weight = the strength of the force of gravity
Draw what the shadows of a tree would look like at:
9:00 AM
12:00 PM (noon)
5:00 PM
9 - long
noon - short
5 pm- long