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
A 1.5 kg bird is gliding at a height of 12 m with a speed of 3.8m/s. The kinetic energy of the bird is 10.83 joules.
Explanation:
Kinetic energy can be defined as,The kinetic energy (KE) of an object is the energy that the object possesses due to its motion.
The Kinetic energy can be calculated by using formula,
Kinetic Energy: KE = 1/2 (mv 2)
Where, m = Mass, v = Velocity.
Here in this case the bird mass is 1.5kg and is gliding with velocity 3.8m/s
hence, KE= 1/2*(1.5)×(3.8)^2
=0.5×1.5×3.8×3.8
=10.83Joules
I am not sure but i think the answer is C
Potential energy = mass x gravity x height
P.E = 4 x 9.8 x 3
P.E = 117.6 J