Question 1 of 10 Which of these is an example of a composite material?
A. Aluminum for the outer layer of an airplane
B. Plywood used in houses, which contains wood pieces glued
together in different directions
C. Wood planks used as beams to support roofs
D. Steel cables designed to be lightweight and strong

The answer is falsegravitational force is independent of medium and depends only on the masses of the two objects and the distance between them.

Ansaquatic plants;  

Reaction involved in present system is :   c12h22o11 + h2o → 2 c6h12o6the reaction system is obeying following rate law:   rate = k[c12h22o11]thus, it is a first order reaction.now, for 1st order reactionrate constant (k) =  given: initial conc. = 3.0 g, final conc. = 2.7 g, t = 2.5 h∴rate constant (k) =  ∴ k = 0.04215 h-1now, for 1st order reaction, half life = 0.693/k = 0.693/0.04215 = 16.4 hthus correct answer is option b