Force & Motion

High-accuracy Monkey & Hunter Set


【Product Description】

Ball collision system with a high accuracy hit probability, known as “the Monkey and the Hunter”.

【Overall Advantages to Users】

  • Compared with conventional type of apparatus, this product better demonstrates an essential and classic physics problem, known as “the Monkey and the Hunter”, by providing students with a high-accuracy collision of a projectile (an aluminum ball used as a bullet shot by a hunter) with a free-falling object (a plastic ball used as a monkey falling from a tree).

  • Achieved highly accurate and repeatable collision of a small projectile (an aluminum ball of diameter 25mm) with a small free-falling object (a plastic ball of diameter 35mm) over the airline distance of around 1500mm.


  • The monkey and hunter
  • Projectile motion
  • Projectiles launched at horizontally
  • Projectiles launched at an angle
  • Two-dimensional motion




【To all users】

  • A long aiming guide rail (1650mm) raises the collision probability of two balls in the air.
  • Comparison experiments can be easily carried because the ball launching (initial) speed is adjustable in steps.
  • In case of the collision experiment in horizontal position, the guide rail must be hold by a stand because of its legs’ height.
  • The ball dropping device at top of the guide rail and the ball launching device at bottom of the guid rail are controlled by electricity. Therefore, the system needs a DC power supply to operate.

【To teachers】

  • For even higher effectivity demonstration, it is good to take a high speed movie by digital camera or a smart phone.
  • Size after assembly (excluding a support stand): 1,900 × 570 × 720mm
  • Boom: 1,900mm (the full-length rail after two rails is united with each other)
  • Ball release unit: Electromagnetic type (Rated voltage: DC 2.5V, Maximum input voltage: 4.0V)
  • Ball launcher: Spring plunger type
  •  Accessories:
    • Free-falling object: φ35mm Plastic ball x2 pcs
    • Projectile: φ25mm Aluminum ball x2 pcs
    • Metallic ring-shaped plumb connected with a magnet via a kite string (1m) x1 PC

Required equipment (not included, prepare beforehand by yourself): a DC power supply (2.5V recommended, max. 4V, 5A), a support stand with a clamp to fix a supporting rod (8mm diameter).

Teacher's Resources

  • [ MANUAL ] High-accuracy type Monkey & Hunter


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