Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
Define Newton's First Law of Motion
|
Objects at rest tend to remain at rest. Objects in motion tend to stay in motion traveling at a constant speed and in the same direction.
|
|
|
Define inertia.
|
the tendancy of an object to remain at rest or in motion.
|
|
|
Why do car manufacturers use crash test dummies?
|
to discover what protection is needed, to try various designs, to refine their designs and test for safty.
|
|
|
Does a passenger sitting still on a bus demonstrate inertia?
|
yes: An object at rest will tend to stay at rest.
|
|
|
Does a passenger falling forward on a bus demonstrate inertia?
|
yes: an object in motion will tend to stay in motion.
|
|
|
Define Newton's Second Law of Motion?
|
An object that is at rest or in motion will not change its condition unless something causes the change.(a Force acts on it)
|
|
|
Define force.
|
A push or a pull.
|
|
|
Define Newton.
|
A unit used to meausre force. (The force needed to accelerate a one-kilogram object by one meter per second every second.)
|
|
|
Formula for Force. (know how to solve for this.)
see pg. F 66-68 in book. |
Force = mass x acceleration
F=m x a |
|
|
Formula for Newton> (know how to solve for this.)
see pg. F66-68 in book |
N=kg x m/s
|
|
|
There are two balls, a tennis ball and bowling ball. Which ball will accelerate less?
|
The ball with the greater mass (bowling ball) will accelerate less.
|
|
|
What happens when the force is increased on an object?
|
The greater the force the greater the acceleration.
(think about a home run in baseball vs. a run to first base) |
|
|
Define Friction.
|
The force that occurs between surfaces that are in contact with each other. friction resists the motion of one surface over another.
|
|
|
How can friction be increased?
|
Put sand on a slippery surface. Ex: Winter with ice on the road. Salt or sand is put on the ice to increase friction and stop slipping.
|
|
|
Do wheels increase or decrease fricition?
|
Wheels decrease friction.
|
|
|
Name some items that will increase friction.
|
gravel, sandpaper, carpet, cleats (items that are rough)
brakes of a car.) Friction helps slow an object down. |
|
|
Name some items that will decrease friction.
|
oil, butter, hand lotion, wax, fine powder, ball bearings (smooth/slippery items)
|
|
|
Why are footballs and basketballs surfaces rough?
|
Rough surfaces increase friction which helps with grip of the ball.
|
|
|
What would happen if a hocey puck was rough rather than smooth?
|
The puck would not slide easily over the ice.
|
|
|
Which has more friction: sliding or rolling?
|
sliding friction is greater than rolling friction.
|
