Answer:
= 1.9 cm
Explanation:
The magnification of a microscope is the product of the magnification of the eyepiece by the magnifier with the objective
M = M₀ 
Where M₀ is the magnification of the objective and
is the magnification of the eyepiece.
The eyepiece is focused to the near vision point (d = 25 cm)
= 25 /
The objective is focused on the distances of the tube (L)
M₀ = -L / f₀
Substituting
M = - L/f₀ 25/
1) Let's look for the focal length of the eyepiece (faith)
= - L 25 / f₀ M
M = 400X = -400
= - 12 25 /0.40 (-400)
= 1.875 cm
Let's approximate two significant figures
= 1.9 cm
Answer:

Explanation:
Using the first law of thermodynamics:

Where
is the change in the internal energy of the system, in this case
,
is the heat tranferred, and
is the work,
with a negative sign since the work is done by the system.
From the previous equation we solve for heat, because it is the unknown variable in this problem

And replacing the known values:



The negative sign shows us that the heat is tranferred from the system into the surroundings.
Mass of the object is given as

now the speed of object is given as

here we know that


now we will have

now we will have kinetic energy of the object as



now the power is defined as rate of energy
so here we can find power as


so above is the power used for the object
Answer:
Sound wave is a longitudinal wave that propagates in a medium
Explanation:
<em>Part A:</em> (C) Sound wave is propagation of pressure fluctuations in a medium.
<em>Part B: </em>(C) Pressure fluctuations travel along the direction of propagation of the sound wave.
<em>Part C: </em>(A) Yes air play a role in the propagation of the human voice from one end of the lecture hall to the other.