Given,
Radius of curvature of concave mirror = 1.6m
We know that ,
Focal length = radius/2
Hence ,
Focal length of concave mirror = radius of concave mirror /2
=> F = 1.6/2
=> F = 0.8m
Hence the focal length of concave mirror is 0.8 m
Explanation:
equating the parameters into the formula, it's gonna be
= ½ × 60 × 20²
= ½ × 60 × 400
= ½ × 24000
K.E = 12000J
Answer:

Explanation:
h = Planck's constant = 
m = Mass of electron = 
k = Coulomb constant = 
e = Charge of electron = 
n = 1 (ground state)
Angular momentum is given by

From Bohr's atomic model we have


The centripetal force will balance the electrostatic force

The diameter is 
C) In the absence of an unbalanced force, an object at rest will stay at rest and an object in motion will stay in motion.
hope this helps and have a great day :)
a) At a position of 2.0m, the Initial energy is
all made up of the potential energy=m*g*hi<span>
and meanwhile at 1.5 all its energy is also potential energy=m*g*hf
The percentage of energy remaining is E=m*g*hi/m*g*hf x 100
and since mass and gravity are constant so it leaves us with
just E=hi/hf
which 1.5/2.0 x100= 75% so we see that we lost 25% of the
energy or 0.25 in fraction
b) Here use the equation vf^2=vi^2+2gd
<span>where g is gravity, vf is the final velocity and vi is the
initial velocity while d is the distance travelled
so in here we are looking for the vi so let us isolate that
variable
we know that at maximum height or peak, the velocity is 0 so
vf is 0
therefore,</span></span>
vi =sqrt(-2gd) <span>
vi =sqrt(-2x-9.81x1.5) </span>
<span>vi =5.4 m/s
<span>c) The energy was converted to heat due to friction with the
air and the ground.</span></span>