Who was the first head of the nasa space program was sergei korolov, but the russians never identified him by name. what did they call him in public?

Adding more pulleys to a system of pulleys needed to lift an object. a. increases the force b. decreases the force c. increases the amount of work d. decreases the amount of work

In positive numbers less than 1, the zeros between the decimal point and non zero are significant

An object of dimensions 50 cm x 40 cm x 0.20 cm has a mass 60g. find its density in g/cm3 and kg/ m3