When two or more simple machines work together, they are called a(n)
a. compound machine
c. screw
b. effort machine
d. simple machine

If the moon has a diameter of 2,159.14 miles, what is the maximum distance that it could be observed by the naked eye with enough detail that you could distinguish it from other celestial bodies (assuming that you have 20/20 vision)

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

If a tank filled with water contains a block and the height of the water above point a within the block is 0.8 meter, what is the pressure at point a?