Answer:

Explanation:
Missing question:
What is the object's acceleration?
Solution:
The acceleration of an object is given by

where
v is the final velocity
u is the initial velocity
t is the time taken for the change in velocity
For the object in this problem,
u = +25 m/s
v = +15 m/s
t = 2.0 s
Substituting,

And the acceleration is negative because its direction is opposite to that of the velocity.
Answer:
Height of tree = 78.35 meters.
Explanation:
We have
1 meter = 3.28 feet
That is

Here height of tree = 257 ft
Height of tree = 257 x 0.3048 = 78.35 m
Height of tree = 78.35 meters.
Answer:
Because a person may be pulled in the direction of the moving train. Thereby causing accident
Explanation:
According to Daniel Bernoulli's theorem, he was widely known as a Mathematician. He stated that due to the higher velocity of a moving train, there is higher kinetic energy in terms of volume around it, while the air pressure between the person and the train becomes lower.
As a result, a person near a moving train may be pulled in the direction of the moving train. Thereby causing accidents that may lead to death.
Answer:
(1)
(2)
but
transition not allowed.
Explanation:
Atoms can be described by the quantum number n, spin quantum number S, angular momentum quantum number L, and total angular momentum quantum number J. Based on approximation Russel- Saunders electron coupling, the atomic term symbol can be written as
.
The conditions or selection rule to promoting the electron are discussed below:
(1) The total spin should not change that is
.
(2) The total angular momentum change should be,
but
transition not allowed.