forces & net force
A soccer ball is sitting still on the ground. Someone kicks it, and the ball begins moving. Were the forces on the ball balanced or unbalanced when it began moving?
Unbalanced
A student walks 8 meters east, then 3 meters west. What is their displacement?
5 meters east.
A swimmer pushes backwards with their arms, and the water pushes the swimmer forward. Which Newton's Law explains this?
Newton's Third Law - the Law of Action/Reaction
You pull a wagon with a rope. What type of force is carried through the rope?
Tension
In tug of war, neither team is moving. Why?
The forces are balanced.
What three things can you use to describe an object's location?
Distance, direction, and a reference point
A student walks 8 meters, then 3 meters west. What is their total distance traveled?
11 meters.
A car suddenly stops, but the passengers' bodies continue moving forward. Which of Newton's Laws explains why?
Newton's First Law/The Law of Inertia
A beach ball is floating in a pool. What force from the water pushes upward on the ball?
Buoyant force
What happens to an object's motion when the forces acting on it are unbalanced?
It changes.
What is a reference point?
An object or location used to determine whether something has moved.
The change in an object's location from start to finish, including direction.
What is inertia?
An object's resistance to a change in motion
A book is sitting on a desk. What force from the desk supports the book?
Normal force.
When the forces acting on an object are equal and opposite, what are those forces called?
Balanced forces.
What is motion?
A change in an object's location over time.
What is distance?
The total amount of ground an object travels.
Which Newton's Law is also called the Law of Inertia?
Newton's First Law.
You push a shopping cart forward with your hands. What type of force are you applying?
Applied force.
What are the two things that every force has?
strength and direction
You tell someone, "The snail is 5 meters southeast of the rock pile." What information about the snail's location have you given them?
Its distance and direction away from the reference point.
A student walks 10 meters north, then 10 meters south. What is their distance traveled and their displacement?
Distance = 20 meters; displacement = 0 meters
Two soccer balls have the same mass. One is kicked with more force than the other. Which ball will have greater acceleration, according to Newton's Second Law?
The ball kicked with more force will have more acceleration.
A student kicks a soccer ball. The kick causes the ball to start moving, and the ball eventually slows down as it travels across the grass. Name two forces involved in this situation and explain what each one does.
Applied force starts the ball moving, and friction opposes its motion, causing it to slow down.