Answer:
Between the principal focus and the pole of the mirror
Here are the answers to the question. Make sure to give a valid reason, please.
A. the sum of the protons and neutrons in one atom of the element.
B. a ratio based on the mass of a carbon-12 atom.
C. a weighted average of the masses of an element's isotopes.
D. twice the number of protons in one atom of the element.
Answer:
The true course:
north of east
The ground speed of the plane: 96.68 m/s
Explanation:
Given:
= velocity of wind = 
= velocity of plane in still air = 
Assume:
= resultant velocity of the plane
= direction of the plane with the east
Since the resultant is the vector addition of all the vectors. So, the resultant velocity of the plane will be the vector sum of the wind velocity and the plane velocity in still air.

Let us find the direction of this resultant velocity with respect to east direction:

This means the the true course of the plane is in the direction of
north of east.
The ground speed will be the magnitude of the resultant velocity of the plane.

Hence, the ground speed of the plane is 96.68 km/h.
Explanation:
Given that,
Wavelength = 6.0 nm
de Broglie wavelength = 6.0 nm
(a). We need to calculate the energy of photon
Using formula of energy



(b). We need to calculate the kinetic energy of an electron
Using formula of kinetic energy


Put the value into the formula


(c). We need to calculate the energy of photon
Using formula of energy



(d). We need to calculate the kinetic energy of an electron
Using formula of kinetic energy


Put the value into the formula


Hence, This is the required solution.
Answer:
568.18 N
Explanation:
From the question,
The formula for gravitational potential is given as
Ep = mgh........................ Equation 1
Where Ep = Gravitational potential, m = mass of the diver,h = Height.
But,
W = mg.................... Equation 2
Where W = weight of the diver.
Substitute equation 2 into equation 1
Ep = Wh
Make W the subject of the equation
W = Ep/h................... Equation 3
Given: Ep = 25000 J, h = 44 m
Substitute into equation 3
W = 25000/44
W = 568.18 N.
Hence the weight of the diver = 568.18 N