Ultimate 1 Flashcards

A class 1 lever has its fulcrum positioned 0.5 m from a 600 N load and 2.0 m from the effort point. What effort force is needed to balance the load?

Answer: 150 N

Using the lever principle: Load × load arm = Effort × effort arm. So 600 N × 0.5 m = Effort × 2.0 m, giving Effort = 300 / 2.0 = 150 N.

An inclined plane is 5 meters long and rises 1 meter vertically. What is the mechanical advantage of this inclined plane?

Answer: 5

The mechanical advantage of an inclined plane equals the slope length divided by the vertical height: MA = 5 m ÷ 1 m = 5. A longer ramp for the same rise multiplies your force by 5.

A driving pulley with a diameter of 150 mm rotates at 800 RPM and is connected by a belt to a driven pulley with a diameter of 400 mm. What is the speed of the driven pulley?

Answer: 300 RPM

Belt speed is constant, so N₁ × D₁ = N₂ × D₂. Therefore N₂ = 800 × 150 / 400 = 300 RPM. The larger pulley rotates slower in proportion to the diameter ratio.

Two springs with spring constants k₁ = 200 N/m and k₂ = 300 N/m are connected in series. What is the combined spring constant?

Answer: 120 N/m

For springs in series: 1/k = 1/k₁ + 1/k₂ = 1/200 + 1/300 = 5/600, so k = 120 N/m. Springs in series are always softer (lower k) than either individual spring.

A wrench applies a force of 80 N perpendicular to its handle at a distance of 0.25 m from the center of a bolt. What torque is applied to the bolt?

Answer: 20 N·m

Torque = Force × perpendicular distance = 80 N × 0.25 m = 20 N·m. The torque depends on both the force applied and how far from the pivot it acts.

A motor lifts a 200 kg load to a height of 10 m in 25 seconds. What is the power output of the motor? (g = 10 m/s²)

Answer: 800 W

Work done = mgh = 200 kg × 10 m/s² × 10 m = 20,000 J. Power = Work / time = 20,000 J / 25 s = 800 W. Power tells you how fast the work is done.