Assertion (A) Most of the synthetic polymers are not biodegradable.
Reason (R) Polymerisation process induces toxic polymerisation.
Assertion (A) Graphite is an example of tetragonal crystal system.
Reason (R) For a tetragonal system, $$a=b \neq c$$ and $$\alpha=\beta=90^{\circ}, \gamma=120^{\circ}$$.
A wooden wedge of mass $$M$$ and inclination angle $$(\alpha)$$ rest on a smooth floor. A block of mass $m$ is kept on wedge. A force $$F$$ is applied on the wedge as shown in the figure such that block remains stationary with respect to wedge. So, magnitude of force $$F$$ is
A piece of ice slides down a rough inclined plane at $$45^{\circ}$$ inclination in twice the time that it takes to slide down an identical but frictionless inclined plane. What is the coefficient of friction between ice and incline?