Volume of the original block (V) of length (l), width (w) and height (h) is given by the following equation
hence volume of original block, V = (6)(4)(10) = 
Now say we cut this block in two equal parts, than the length of new block will be 
; where as its width and height will be same as of original block i.e. 4 cm and 10 cm respectively.
So, Volume of half-block is 
; or we can say that the volume of half-block is half that of orignal block.
Answer:
Recoil speed, 
Explanation:
Given that,
Mass of the comet fragment, 
Speed of the comet fragment, 
Mass of Callisto, 
The collision is completely inelastic. Assuming for this calculation that Callisto's initial momentum is zero. So,
V is recoil speed of Callisto immediately after the collision.
So, the recoil speed of Callisto immediately after the collision is
Because Mars is further from the sun than Earth is, thus the gravitational pull is not as great on Mars as it is on Earth, making us lighter :)
