Vocabulary
Force that pulls things toward the center of Earth.
Gravity
Which requires more force; a baseball player bunting a ball or hitting a home run.
Hitting a home run.
What are some ways an object can move?
Up and down, back and forth, straight, in a curve.
What force acts only when objects are touching?
Friction
What force puts a roller coaster in motion at the top of a hill?
Gravity
Force that acts when two surfaces rub together.
Friction
Two children are playing tug of war. They are not moving. Why would this occur?
They are using equal force to pull on the rope.
You are bouncing a kick ball on the ground. Describe its motion.
It moves down to the ground and up to your hand again.
What creates more friction, a smooth floor or a floor with a carpet on it?
A floor with a carpet.
How are weight and gravity related?
Weight is the measure of Earth's gravity on an object.
The distance an object moves in a period of time.
Speed
What causes the motion of an object to change?
A force.
How can the position and motion of an object be related?
Motion is the change in position in an object.
What happens to your motion when there is more friction.
You slow down or come to a stop.
What happens if you let a ball go at the top of a slide?
It will roll to the bottom of the slide.
A push or a pull.
Force
When a baseball player throws the ball to the batter, is it an equal or unequal force and why?
Unequal, the pitcher starts with a ball that is not moving, then pushes it to make it move.
A quitar string makes noise when it vibrates. Describe the motion of the guitar string.
A vibrating string moves back and forth.
What instrument is used to measure force? What is its unit of measurement?
Spring scale. Newton.
If there were no gravity, what would happen to a ball if you threw it up in the air?
The ball would keep moving up without slowing down because there is no force to change its motion.
A change in position.
Motion
A quickly rolling ball suddenly stops moving. What must have caused the motion of the ball to change?
A force must have acted on the ball to cause it to stop rolling.
How are speed and motion related?
When an object moves in a straight line it can move fast. If it comes to a turn, it has to decrease its speed to make the turn.
A boy wants to make it easier to grip the handlebars of his bike so his hands don't slip. Should he cover them with a rough material or a smooth material? Why?
Rough material, because it would create more friction keeping his hands from slipping.
Compare the force of gravity on a car and the force of gravity on a bike. How and why are they different?
The force of gravity of the car is stronger. Therefore, the car weighs more.