Which description best contrasts pneumatics and hydraulics for typical VEX robots?

• A. Pneumatics use incompressible fluid and produce high forces.
• B. Hydraulics use compressible air for rapid cycling.
• C. Pneumatics use compressible air and are generally faster for light actions; hydraulics provide higher force with incompressible fluid but can be slower.
• D. Hydraulics are lighter and simpler.

Answer: (C)

Pneumatics use compressed air, which is easily compressible, so actuators move quickly and are well-suited for light actions. The trade-off is that the force they can produce is relatively modest and can vary with speed and position due to air’s compressibility. Hydraulics, on the other hand, use an incompressible fluid (like oil). This lets small input pressures create much larger forces, giving high-power actuation, but the system tends to be slower because moving fluid through restrictors and pumps takes time and the components add mass and complexity. So the description that matches typical VEX use is that pneumatics are fast for light tasks, while hydraulics deliver higher force at the cost of slower, heavier systems.