A construction worker uses a board and log as a lever to lift a heavy rock. If the input arm is 5 meters long and the output arm is 2 meters long, what is the mechanical advantage of the lever?
a. 2.5
b. 7
c. 0.4
d. 10
The mechanical advantage of a lever is determined by the ratio of the lengths of the input arm to the output arm. In this case, the input arm is 5 meters long and the output arm is 2 meters long.
Mechanical Advantage = Length of Input Arm / Length of Output Arm
= 5 meters / 2 meters
= 2.5
Therefore, the mechanical advantage of the lever is 2.5. So, the correct answer is a. 2.5.