Energy & Motion
What is energy?
The ability to cause motion or create change.
What does rubbing your hands together produce?
Heat, due to friction.
What is always changing with an object in motion?
Its position.
What two measurements are needed to find an object's speed?
Distance and time.
Why do metal chains on a swing set feel hot on a sunny day?
They conduct heat from the Sun.
What happens when energy is transferred to an object/you have an unbalanced force?
It can cause an object to move or change.
Why do metal objects feel hotter than plastic ones in the sun?
Metal is a better conductor of heat.
What is happening to a baseball right before a player hits it?
Its position is changing.
What tools would you use to measure speed in an experiment?
A stopwatch and a meter stick.
Why is a metal spoon's handle sometimes covered in plastic?
Plastic prevents heat transfer to your hand because its an insulator.
Give an example of energy causing motion.
A rolling ball, a windmill spinning, a car driving, etc.
Two students test how different materials affect heat transfer. One wraps a can of warm water in aluminum foil, and the other wraps it in a wool cloth. Which will stay warm longer and why?
The wool cloth because it is an insulator, while aluminum foil is a conductor that allows heat to escape.
If an object is moving, what must be true about its position?
It is constantly changing.
Which student ran faster? One who took 5 seconds or one who took 10 seconds to run the same distance?
The student who took 5 seconds.
What force slows down a moving object when it rubs against another surface?
Friction
How does heat energy transfer from one object to another?
Heat moves from hot to cold or through conduction, convection, & radiation.
Why does hot chocolate stay warmer in a ceramic cup longer than a paper cup?
Ceramic is a better insulator than paper.
How can an object's motion change without stopping or accelerating?
An object can change direction.
How can you tell if one car is moving faster than another?
It travels a greater distance in the same amount of time.
Name 3 surfaces that have very little friction.
Ice, tile, wood, etc.
What is mechanical energy?
Kinetic+potential energy. The energy of motion.
Name two things that give off both light and heat.
The sun, fire, a light bulb, etc.
What 3 things about motion can change when riding a roller coaster?
Position, speed, & direction.
If a ball rolls 2000 meters in 10 seconds, what is its speed?
200 meters per second.
What's Newton's 1st Law of Motion?
An object at rest will stay at rest unless a force acts upon it. An object in motion will stay moving in the same direction and same speed, unless a force acts upon it.