The energy carried by a single photon of frequency f is given by:

where

is the Planck constant. In our problem, the frequency of the photon is

, and by using these numbers we can find the energy of the photon:
Answer:
K = -½U
Explanation:
From Newton's law of gravitation, the formula for gravitational potential energy is;
U = -GMm/R
Where,
G is gravitational constant
M and m are the two masses exerting the forces
R is the distance between the two objects
Now, in the question, we are given that kinetic energy is;
K = GMm/2R
Re-rranging, we have;
K = ½(GMm/R)
Comparing the equation of kinetic energy to that of potential energy, we can derive that gravitational kinetic energy can be expressed in terms of potential energy as;
K = -½U
A cart is pulled by horizontal force such that it moves with constant velocity
So here since velocity is constant we can say that its acceleration will be ZERO
now here for zero acceleration we can say

So here we will have

here we know that

so we will have


so here applied force on handle will be
<em>b. 10 N</em>
Given: Mass m = 0.50 Kg; Force = Weight = mg F = (0.50 Kg)(9.8 m/s²)
F = 4.9 N
Displacement x = 3.0 cm convert to meter x = 0.03 m
Required: Spring constant k = "
Formula: F = kx
k = F/x
k = 4.9 N/0.03 m
k = 163.33 N/m
6. F- DNA
7. C
8. G
9. D
I believe these are correct, hope this helps.