Answer: The area of brick in contact with the floor is 1539
.
Explanation:
Given: Length = 19 cm
Width = 9 cm
Height = 9 cm
As the brick is rectangular in shape. Hence, its area will be calculated as follows.

Substitute the values into above formula as follows.

Thus, we can conclude that area of brick in contact with the floor is 1539
.
Answer: a) 19.21m b) 3.92secs
Explanation:
a) Maximum height reached by the object is the height reached by an object before falling freely under gravity.
Maximum height = U²/2g
U is the initial velocity = 19.6m/s
g is acceleration due to gravity = 10m/s²
Maximum Height = 19.6²/2(10)
H = 19.21m
b) The time elapsed before the stone hits the ground is the time of flight T= 2U/g
T= 2(19.6)/10
T = 39.2/10
Time elapsed is 3.92secs
This applies to nuclear reactions, specifically nuclear fission.
This huge release of energy has been used in atomic bombs and in the nuclear reactors that generate electricity.