mass of rock remains constant
Answer:
2.62seconds
Explanation:
Echo occurs when sound reflects and causing a delay before getting to the listener.
Let x be the distance from between the source and the reflector
t be the time taken for the echo to occur
v be the velocity of sound in air.
Using the relationship 2x = vt
t = 2x/v
Given x = 450metres
v = 343m/s
t = 2(450)/343
t = 900/343
t = 2.62seconds
It will take 2.62 seconds for him to hear his own voice echo off of the wall.
An atom is the smallest unit of an element
We can solve the problem by requiring the equilibrium of the forces and the equilibrium of torques.
1) Equilibrium of forces:
where
is the weight of the person
is the weight of the scaffold
Re-arranging, we can write the equation as
(1)
2) Equilibrium of torques:
where 3 m and 2 m are the distances of the forces from the center of mass of the scaffold.
Using
and replacing T1 with (1), we find
from which we find
And then, substituting T2 into (1), we find
There are several information's of importance already given in the question. Based on those information's the answer can be deduced.
Volage = 19 V
Current = 5 A
Power = Voltage x Current
= 19 x 5
= 95 Watt
From the above deduction, it can be concluded that the correct option among all the options that are given in the question is the second option or 95 W.