An agricultural telehandler is a farm machine designed to lift, carry, and place heavy loads such as hay bales, seed pallets, fertilizer bags, and feed bins. Its telescopic boom gives it more reach than a standard loader, making it useful in barns, yards, fields, and storage sheds. Understanding how a telehandler works helps students connect physics ideas like force, torque, stability, hydraulics, and traction to real farm equipment.
Safe operation depends on knowing how load weight, boom angle, ground slope, and center of mass affect the machine.
Key Facts
- Torque = force x perpendicular distance, so τ = Fd.
- A longer boom increases the load moment because the load is farther from the front axle.
- For static balance, clockwise torque must equal counterclockwise torque: Στ = 0.
- Hydraulic pressure creates lifting force: F = PA, where P is pressure and A is piston area.
- Power relates to work and time: P = W/t.
- Traction depends on friction: maximum friction force is Ff = μN.
Vocabulary
- Telehandler
- A telehandler is a mobile lifting machine with a telescopic boom used to move loads forward, upward, and outward.
- Telescopic boom
- A telescopic boom is an extendable arm made of sliding sections that changes the machine's reach and lifting height.
- Load moment
- Load moment is the turning effect caused by a load, equal to the load force multiplied by its distance from the pivot.
- Hydraulic cylinder
- A hydraulic cylinder uses pressurized fluid to push a piston and produce a large linear force.
- Center of mass
- The center of mass is the average position of an object's mass where its weight can be treated as acting.
Common Mistakes to Avoid
- Ignoring boom extension, because the same load becomes more likely to tip the machine when it is farther from the front axle.
- Treating load weight and mass as the same thing, because weight is a force equal to mg while mass is the amount of matter.
- Assuming hydraulic pressure alone determines lifting ability, because the piston area and boom geometry also affect the output force and torque.
- Lifting on a slope as if the machine were on level ground, because a slope shifts the center of mass and reduces the stability margin.
Practice Questions
- 1 A 600 kg hay bale is lifted so its center is 2.5 m in front of the front axle. Using g = 9.8 m/s², calculate the load moment about the front axle.
- 2 A hydraulic cylinder has a piston area of 0.004 m² and fluid pressure of 12,000,000 Pa. What force can the cylinder produce?
- 3 A telehandler can lift a pallet safely when the boom is partly retracted, but not when the boom is fully extended. Explain this using torque, center of mass, and stability.