Forces
When a friend pitches a ball to another who hits it back to the pitcher, a scientist would see this as an example of?
A force that changes the ball's direction.
What is the energy of an object in motion?
Kinetic endergy
Why is it that when sandpaper is rubbed over wood, both surfaces become warm?
This is a result of friction
When a battery is used to light a bulb, chemical energy is changed to which type of energy?
The chemical energy in the battery is changed into electrical energy.
Caiden is planning a skateboard race. Which would be the best surface for his race?
wood chips blacktop
sand grass
Blacktop because it has less friction and he could go faster.
What can a force cause an object to do?
Move, change direction of movement, stop moving or change speed. It will NOT make the object colder.
Where on a slide would a child have the most potential energy?
The child sitting at the top of the slide.
Why do objects weigh less on the moon than on Earth?
The moon has less gravity than the Earth
To pedal a bike which form of energy does a person use?
Mechanical energy is what is used to pedal a bike.
Which simple machine would you use to roll a barrel into the back of a truck?
A inclined plane which is another name for a ramp.
How can you tell that an object is moving?
Compare it to other objects or its background.
Which of the following would use chemical energy?
windup toy rubber band car
battery powered car television
The battery powered car would use chemical energy.
If there would no air friction would a thrown ball still fall to the ground?
Yes because the force of gravity would still work on the ball.
Which two forms of energy are produced by a burning candle?
A burning candle will produce both heat and light energy.
To do work there must be force and distance. Which is work?
watching TV
carrying a box across the room
observing a science experiment
pushing a large boulder that will not move
Carrying a box across a room has both force and distance so it is work.
What is the force that pulls any two objects toward each other?
Gravity or gravitation
When a stick is rubbed over a comb the mechanical energy is changed into which form of energy?
The mechanical energy is changed into sound energy.
What is the force that slows down moving objects?
Friction is the force that will slow down moving objects.
What happens to the potential and kinetic energy of a leaf as it falls from the branch to the ground.
The leaf's potential energy decreases as it falls while it kinetic energy increases.
Why does it take more force to push a sled with 2 friends in it over ice, than an empty sled over ice?
The friends add more mass and you need more force to push mass.
If you wanted to move a small wooden block the farthest which ball would you use and why?
5 gram ball 10 gram ball
15 gram ball 20 gram ball
You would use the 20 gram ball because it would exert more force on the wooden block.
Which form of energy is stored in batteries inside a flashlight?
Chemical energy is stored in batteries.
Would it take more force or less force to push a sled over a rocky road than over ice?
It will take more force to push a sled over a rocky road because there is more friction on the rocky road than on the ice.
Can energy change forms?
Yes, for example chemical energy in a battery can be changed to electrical energy and then to light energy in a flashlight.
What two forces work on a ball that you throw into the air?
Friction will slow the ball down and gravity will cause it to fall back to Earth.