Answer:
A. The particle model, because only high-energy frequencies of light can remove electrons .
Explanation:
Each photon of blue light has higher energy than each photon of red light has . So when each photon strikes each electron , it gets ejected . But the photon of red light has not sufficient energy to eject electron . Once the photon of red light strikes the electron , the energy is wasted off . Energy of photon can not be accumulated . Thus photon behaves like particle .
Answer:
Acceleration of the ship, 
Explanation:
It is given that,
Mass of both ships, 
Distance between two ships, d = 110 m
The gravitational force between two ships is given by :


F = 8.38 N
Let a is the acceleration. Now, using second law of motion as :



So, the acceleration of either ship due to the gravitational attraction of the other is
. Hence, this is the required solution.
Answer:
Q = 913.9 gpm
Explanation:
The Hazen Williams equation can be written as follows:

where,
P = Friction Loss per foot of pipe =
= 4 x 10⁻⁴
Q = Flow Rate in gallon/min (gpm) = ?
d = pipe diameter in inches = (400 mm)(0.0393701 in/1 mm) = 15.75 in
C = roughness coefficient = 100
Therefore,

<u>Q = 913.9 gpm</u>
The correct answer is:
Work is negative, the environment did work on the object, and the energy of the system decreases.
In fact, the work-energy theorem states that the work done by the system is equal to its variation of kinetic energy:

In this problem, the variation of kinetic energy
is negative (because the final velocity is less than the initial velocity), so the work is negative, and this means that the environment did work on the object, and its energy decreased.