The record number of boat lifts, including the boat and its ten crew members, was achieved by Sami Heinonen and Juha-Matti Räsänen of Finland in 2000. They lifted a total mass of 653.2 kg approximately 4 in. off the ground a total of 24 times. Estimate the total work done by the two men on the boat in this record lift, ignoring the negative work done by the men when they lowered the boat back to the ground.

Explanation:

Mechanical Work

A force F applied to an object and causing it to displace a distance x parallel to the force, does a work W given by

When an object is lifted by a distance h, the work is done against the force of gravity, or the weight of the object

The boat is lifted x=4 inches = 4*0.0254 = 0.1016 m

The work done every time they lift the boat is

The total work done by the team is 24 times that particular work

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg