Why all factors of body are favourable for diffusion of `O_(2)` from alveoli to tissues and of `CO_(2)` from tissue cells to alveolis ?

How do germ cells make a single set of genes from the normal two copies in all other cells of body ?

A body is projectd with the velcity (U_1) from the point (A) as shown in Fig. 2. (d). 37. At the same time another body u2 is projected vertcally upwards with the velcoity u_2 from the point (B) .What should be the value of u_1//u_2 for both the bodies to collide ? .

From a uniform disk of radius R, a circular hole of radius R/2 is cut out. The centre of the hole is at R/2 from the centre of the original disc. Locate the centre of gravity of the resulting flat body.

Energy required to move a body of mass m from an orbit of radius 2R to 3R is