A team of bicyclists are on bikes that require 512 J of work to ride. It takes 432 J of work for the bike to turn the gears. What is the mechanical efficiency of the bike?

84.4 %

Explanation:

Mechanical efficiency = output work/input work × 100 %

output work = 432 J of work for the bike to turn the gears

input work = 512 J of work to ride.

Mechanical efficiency =  432 J/512 J × 100 %

= 0.844 × 100%

= 84.4 %

falling water hydro = water .. spectcular places these plants are

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