Lesson 3.03j

3.03j Smooth contact Quiz: OCR Maths, Unit 18

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 3.03j, Smooth contact: 20 multiple choice questions for the OCR Maths (H240), Unit 18: Forces and Newton's Laws, written with Revision Ninja.

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The 20 questions

  1. What direction does the normal contact force act relative to a smooth surface?

    • Parallel to surface
    • Vertically upwards
    • Perpendicular to surface
    • At 45 degrees

  2. What is the magnitude of the normal reaction force when contact is lost?

    • Negative value
    • Zero
    • Equal to weight
    • Maximum value

  3. Which force is ignored when a contact surface is modelled as smooth?

    • Tension force
    • Normal reaction
    • Friction force
    • Gravitational force

  4. Newton's third law states that action and reaction forces are equal and what?

    • Variable in magnitude
    • Same in direction
    • Opposite in direction
    • Perpendicular in direction

  5. What is the resultant force on a particle that is in equilibrium?

    • Always positive
    • Equal to mass
    • Zero
    • Equal to weight

  6. What property does a light string have in a mathematical mechanics model?

    • Negligible mass
    • Infinite tension
    • Fixed length
    • High friction

  7. What property does an inextensible string have in mechanics problems?

    • Zero tension
    • Zero mass
    • Constant length
    • Variable length

  8. How does tension change along a light string passing over a smooth pulley?

    • Remains constant
    • Halves at pulley
    • Doubles at pulley
    • Becomes zero

  9. A block of mass 5 kg rests on a smooth horizontal table. What is R?

    • 49 N
    • 5 N
    • 0 N
    • 9.8 N

  10. A particle slides down a smooth plane inclined at 30 degrees. What is its acceleration?

    • 9.8 m s^-2
    • 0 m s^-2
    • 2.45 m s^-2
    • 4.9 m s^-2

  11. Masses of 3 kg and 2 kg hang over a smooth pulley. What is their acceleration?

    • 0.98 m s^-2
    • 9.8 m s^-2
    • 1.96 m s^-2
    • 4.9 m s^-2

  12. An engine of mass 1000 kg pulls a carriage of mass 500 kg. System mass is?

    • 500 kg
    • 1500 kg
    • 1000 kg
    • 2000 kg

  13. Three coplanar forces in equilibrium can be represented by what vector shape?

    • Circle
    • Closed triangle
    • Open square
    • Straight line

  14. A particle of mass m rests on a smooth plane inclined at angle θ. Normal reaction is?

    • mg cos θ
    • mg
    • mg tan θ
    • mg sin θ

  15. What component of weight acts down a smooth slope inclined at angle θ?

    • mg
    • mg tan θ
    • mg cos θ
    • mg sin θ

  16. Two particles connected by a taut inextensible string share which kinematic quantity?

    • Direction of motion
    • Acceleration magnitude
    • Zero velocity
    • Mass

  17. A force F acts at angle θ above the horizontal. What is its horizontal component?

    • F sec θ
    • F sin θ
    • F cos θ
    • F tan θ

  18. Do Newton's third law action-reaction pairs act on the same body or different bodies?

    • Same body
    • Different bodies
    • Three bodies
    • No bodies

  19. A smooth peg exerts a force on a light string. Where does this force point?

    • Vertically downwards
    • Parallel to string
    • Along angle bisector
    • Horizontally

  20. A lift accelerates upwards at 2 m s^-2 with a 70 kg person. Normal reaction is?

    • 546 N
    • 826 N
    • 686 N
    • 140 N

All OCR Maths quizzes