Forces in Action
100: What is a force?
Answer: A push or pull on an object that can cause it to move, stop, or change direction.
100: What is gravity?
Answer: The force of attraction between objects with mass.
100: What is Newton’s First Law called?
Law of Inertia
100: What is the equation for Newton’s Second Law?
Answer: a=Fma = \frac{F}{m}a=mF (Acceleration = Force ÷ Mass)
100: Define balanced forces.
Answer: Forces that are equal in size and opposite in direction; they cause no motion change.
200: What is a contact force?
Answer: A force that requires two objects to touch, such as friction.
200: What two things affect the strength of gravity?
Answer: Mass and distance.
200: State Newton’s First Law.
Answer: An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an unbalanced force.
200: What happens to acceleration if you increase the force?
Answer: Acceleration increases.
200: Define unbalanced forces.
Answer: Forces that are not equal, causing a change in motion.
300: What is a noncontact force?
Answer: A force that acts at a distance, like gravity.
300: What is friction?
Answer: A force that resists motion between two touching surfaces.
300: What is inertia?
Answer: The tendency of an object to resist changes in motion.
300: What happens to acceleration if you increase the mass?
Answer: Acceleration decreases.
300: What is centripetal force?
Answer: A force that keeps an object moving in a circle, directed toward the center.
400: When two forces act in the same direction, how do you find the net force?
Answer: Add them together.
400: Name one way to reduce friction.
Answer: Use lubricants, smooth surfaces, or wheels.
400: Give a real-life example of inertia.
Answer: A seatbelt stopping you from moving forward in a car crash.
400: What are the units for force, mass, and acceleration?
Answer: Force = Newtons (N), Mass = kilograms (kg), Acceleration = meters per second squared (m/s²).
400: Give one real-world example of Newton’s Second Law.
Answer: A lighter object accelerates faster than a heavier one when the same force is applied.
500: What happens when forces are balanced?
Answer: The object’s motion does not change; net force = 0 N.
500: Compare gravity and friction.
Answer: Gravity pulls objects together; friction slows or stops motion.
500: Why does a rolling ball eventually stop moving on Earth?
Answer: Friction and air resistance act against its motion.
500: A 10 N force acts on a 2 kg object. What is its acceleration?
Answer: a=10÷2=5m/s
500: What would happen if there were no friction on Earth?
Answer: Objects would never stop moving once set in motion.