Question

If a load 5
is lifted by applying the effort of 4N when the load is placed 10 cm away from fulcrum in a lever
calculate MA,
VR and efficiency

Answer 1

Answer:

MA= 1.25 , VR =1.25 and efficiency is 100%

Answer 2

Answer:

• M.A = 1.25.
• V.R = 1.25.
• Efficiency = 100% or 1.

Explanation:

Given :

• Load = 5 N
• Effort = 4 N
• Load arm = 10 cm

To find :

• Mechanical advantage.
• Velocity ratio.
• Efficiency.

Solution :

According to principle of moments:

⇒ Load × Load Arm = Effort × Effort Arm.

• 5N × 10 cm = 4N × x
• 50N.cm = 4N × x
• x = 50/4
• x = 12.4

∴ Effort arm = 12.4 cm

Finding mechanical advantage:

⇒ M.A = Load/Effort

• M.A = 5/4
• M.A = 1.25

∴ Mechanical advantage is 1.25.

Finding velocity ratio:

⇒ V.R = Displacement of effort/Displacement of load

• V.R = 12.5/10
• V.R = 1.25

∴ Velocity ratio is 1.25.

Finding efficiency:

⇒ Efficiency = MA/VR × 100%

• Eff = 1.25/1.25 × 100
• Eff = 1 × 100
• Eff = 100

∴ Efficiency is 100% or 1.