Answer:
The building is 61.19 m tall, approximately.
Explanation:
From the parabollic movement trayectory equation,
where H is the initial height of the ball and 
and 
the inital velocities in the vertical and horizontal direction, respectively; we have
.
In this case, the ball landed at the coordinates 
, so
.
Answer:
the mass of the raft is 68.4 kg
Explanation:
Since Mass is defined as Volume times Density, start by calculating the volume of the raft:
Volume = length x width x high = 1.5 m x 1.0 m x 0.12 m = 0.18 m^3
and now multiply it times the given density in order to find its mass:
Mass = Volume x Density = 0.18 m^3 x 380 kg/m^3 = 68.4 kg.
Notice that the m^3 units cancel out (they are in numerator and in denominator) leaving just the kg (a unit of mass) in the answer.
Therefore, the mass of the raft is 68.4 kg
