Let 
be the height of the building and thus the initial height of the ball. The ball's altitude at time 
is given by
where 
is the acceleration due to gravity.
The ball reaches the ground when 
after 
. Solve for :
so the building is about 16 m tall (keeping track of significant digits).
Answer:
The specific gravity of the unkown liquid is 15.
Explanation:
Gauge pressure, at the bottom of the tank in this case, can be calculated from
where 
and 
are the height of the column of oil and the unkown liquid, respectively. Writing for 
, we have
Relative to water, the unknow liquid specific weight is 15 times bigger, therefore this is its specific gravity as well.
Answer:
Explanation:
When we apply a horizontal force of 76 N to a block, the block moves across the floor at a constant speed. So net force on the block is zero .
It implies that a force ( frictional ) acts on it which is equal to 76 N in opposite direction ( friction )
When we apply a greater force on it it starts moving with acceleration .
This time kinetic friction acts on it due to rough ground equal to 76 N .This is limiting friction ( maximum friction )
Net force on the body in later case
= 89 - 76
= 13 N
Force by ground on the block in horizontal direction = 76 N ( FRICTIONAL FORCE )
=
True, the wavelength dies down due to high frequency and low amptitude.
