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
Explanation:
Given that,
Voltage of household line, V = 110 V
Power of the hairdryer, P = 1650 W
During use, the current is about 1.95 cm from the user's hand.
(a) Power is given by :

(b) Again the power is given by :

R is resistance of the dryer

(c) The magnetic field produced by the dryer at the user's hand is given by :

Hence, this is the required solution.
Comparative investigation is a research method that makes comparison across different countries of the world. Limitation : data set in different countries may be defined differently. Benefit : the method is flexible.
Answer:
D
Explanation:
According to research and data, the average cost for a severe injury in a collision is $247,000.
These include traumatic brain injury, severe damage to limbs which could result to loss of the limbs, spinal cord injuries that could result to partial or total paralysis as well as internal damage to organs in the collision.
Answer:
the moment of inertia with the arms extended is Io and when the arms are lowered the moment
I₀/I > 1 ⇒ w > w₀
Explanation:
The angular momentum is conserved if the external torques in the system are zero, this is achieved because the friction with the ice is very small,
L₀ = L_f
I₀ w₀ = I w
w =
w₀
where we see that the angular velocity changes according to the relation of the angular moments, if we approximate the body as a cylinder with two point charges, weight of the arms
I₀ = I_cylinder + 2 m r²
where r is the distance from the center of mass of the arms to the axis of rotation, the moment of inertia of the cylinder does not change, therefore changing the distance of the arms changes the moment of inertia.
If we say that the moment of inertia with the arms extended is Io and when the arms are lowered the moment will be
I <I₀
I₀/I > 1 ⇒ w > w₀
therefore the angular velocity (rotations) must increase
in this way the skater can adjust his spin speed to the musician.