Question

1. how does a lever affect the work required to lift something?

a lever is one type of simple machine, basic devices that reduce the amount of energy required for a task by applying the basic tools or physics. every lever consist of three main components, the effort arm, the resistance arm, and the fulcrum. a lever is balanced when the product of the effort force and the length of the effort arm equals the products of the resistance force and the length of the resistance force arm.
a lever can reduce the amount of work needed to lift something but it does give a trade off! rather than trying to lift an object directly, a lever makes the job easier by dispersing its weight across the entire length of the effort and resistance arms.

1. child a weighs 225 n and sits 1.0 m from the pivot of an adjustable seesaw. if child b weighs 175 n, how far from the pivot should child b sit to balance the weight of child a?

Explanation:

Step1: Recall the lever principle

The lever is in balance when \( F_1 \times d_1 = F_2 \times d_2 \), where \( F_1 \) and \( F_2 \) are the forces (weights in this case), and \( d_1 \) and \( d_2 \) are the distances from the fulcrum. Let \( F_A = 225\space lb \), \( d_A = 1.0\space m \), \( F_B = 175\space lb \), and we need to find \( d_B \).

Step2: Rearrange the formula to solve for \( d_B \)

From \( F_A \times d_A = F_B \times d_B \), we can solve for \( d_B \) by dividing both sides by \( F_B \): \( d_B=\frac{F_A \times d_A}{F_B} \)

Step3: Substitute the values

Substitute \( F_A = 225\space lb \), \( d_A = 1.0\space m \), and \( F_B = 175\space lb \) into the formula: \( d_B=\frac{225\times1.0}{175} \)

Step4: Calculate the value

\( d_B=\frac{225}{175}=\frac{9}{7}\approx1.29\space m \) (rounded to two decimal places)

Answer:

Child B should sit approximately \( \boldsymbol{1.29\space m} \) from the fulcrum.