Question

Which of the following is/are True? (choose from A – E)

(i) The mechanical advantage of class II lever is always greater than 1
(ii) An inclined plane is a simple machine, incline plane with a length of 20 cm and height of 5 cm will have a mechanical advantage of 4.0
(iii) In a class III lever, the load is 70 cm from the fulcrum while the input force is 10 cm from the fulcrum, the mechanical advantage is 0.14
(iv) A scissors is an example of class II lever, the mechanical advantage can be less than 1

Answer 1

Items (i), (ii), and (iii) are true regarding the mechanical advantage of simple machines such as levers and inclined planes. However, statement (iv) is incorrect since scissors are examples of class I levers, and their mechanical advantage can vary.

Step-by-step explanation:

Among the statements provided regarding simple machines and mechanical advantage (MA), the following are True:

• (i) The mechanical advantage of a class II lever is always greater than 1. This is because the effort arm is always longer than the resistance arm in a class II lever.
• (ii) An inclined plane is a simple machine, and an inclined plane with a length of 20 cm and height of 5 cm will have a mechanical advantage of 4.0. This is because MA for an inclined plane is calculated as the ratio of the length to height.
• (iii) In a class III lever, if the load is 70 cm from the fulcrum and the input force is 10 cm from the fulcrum, the mechanical advantage is 0.14. This is determined by dividing the effort arm (10 cm) by the load arm (70 cm).

(iv) A scissors is actually an example of a class I lever, not class II, and the mechanical advantage can vary depending on the length of the effort arm relative to the load arm. Therefore, this statement is not accurate as written.