Q1. What is a force in science?
Answer: A force is a push or a pull applied to an object.
Force
Q2. What two basic actions show the presence of force on a box?
Answer: Pushing and pulling a box show the presence of force.
Q3. What can a force do to a stationary object?
Answer: A force can start the motion of a stationary object.
Q4. How can a force change a moving object’s motion?
Answer: A force can speed up, slow down, or stop a moving object.
Q5. How can a force change the direction of an object?
Answer: A force can change direction, like a bat hitting a ball to send it another way.
Q6. How can a force change the shape of an object?
Answer: A force can change shape by squeezing, stretching, rolling, or twisting an object.
Q7. What is the SI unit of force?
Answer: The SI unit of force is the newton (N).
Q8. What does it mean that forces are interactions?
Answer: It means a force arises when two objects interact, like a hand pushing a table.
Q9. When do balanced forces occur?
Answer: Balanced forces occur when forces cancel out so there is no change in motion.
Balanced Forces
Q10. What happens to the force when the interaction stops?
Answer: The force disappears as soon as the interaction stops.
Q11. What is a contact force?
Answer: A contact force acts only when two objects touch each other.
Q12. What is muscular force?
Answer: Muscular force is the force produced by muscles during actions like lifting or kicking.
Q13. What is friction?
Answer: Friction is a contact force that opposes motion between surfaces in contact.
Q14. How does surface roughness affect friction?
Answer: Rough surfaces produce more friction than smooth surfaces.
Q15. What are drag and air resistance?
Answer: Drag and air resistance are frictional forces from air or water that oppose motion.
Q16. What is a non-contact force?
Answer: A non-contact force acts without physical contact between objects.
Q17. What is magnetic force?
Answer: Magnetic force is the attraction or repulsion between magnets or magnetic materials at a distance.
Q18. What is electrostatic force?
Answer: Electrostatic force is the attraction or repulsion between charged objects without contact.
Q19. What is gravitational force?
Answer: Gravitational force is the pull with which Earth attracts objects towards itself.
Q20. What is weight?
Answer: Weight is the force with which Earth pulls an object due to gravity.
Q21. Does mass change from place to place?
Answer: Mass does not change from place to place.
Q22. Does weight change from place to place?
Answer: Weight can change from place to place if gravity changes.
Q23. What instrument measures weight as a force?
Answer: A spring balance measures weight in newtons.
Q24. What is upthrust or buoyant force?
Answer: Upthrust is the upward force a liquid exerts on an immersed object.
Q25. What does Archimedes’ principle state about floating?
Answer: Archimedes’ principle states that an object experiences an upward force equal to the weight of the displaced liquid.