Forces
When an object is at rest, the forces are __________.
Balanced
Is there much friction as someone is sledding down a hill? Yes or no.
No!
Do the opposite poles of two magnets attract or repel?
What was Elijah's job when he was first working for a train company?
He was the one to "grease the pig"-- oil the engine-- every 30 minutes
What is the pattern of motion for a seesaw?
Up and down
A force is a __________ or __________.
Push or pull
Name an example of friction that is HARMFUL
Possible answers: parts wearing down in an engine, bike tires being worn smooth
Do ends of magnetic poles that are the same attract or repel?
Repel
What do steam engines use to make the trains move?
Steam!
What is the pattern of motion for gravity?
Gravity pulls things to the ground
When an object is moving the forces are _______________.
Unbalanced
Give an example of friction that is HELPFUL
Possible answers: rubbing sticks together to make a fire, brakes on bikes/tires/cars
Compasses work because the center of earth is a __________________.
Magnet
What problems did Elijah's first invention solve? (There are at least two)
Friction causing train parts to wear out and trains from having to stop every 30 minutes.
What did we make with pencils and yarn?
Pendulums
Which type of force works over a distance without touching?
Magnetism
Friction requires objects to be in ___________, or touching.
Contact
Name the two types of metal that are typically magnetic.
Iron and nickel
About how many inventions did Elijah McCoy officially invent during his lifetime?
60
What is the pattern of motion for a pendulum?
Side to side (or back and forth)
Objects that are changing speed or position are said to be in ___________.
Motion
What do we call something that reduces friction?
A lubricant
True or false: Magnetism decreases over a distance.
True
Name the type of train that uses magnets instead of wheels.
Maglev
What is the pattern of motion for a merry-go-round?
Around