Work = (force) x (distance)
80 J = (force) x (4 m)
Force = (80 J) / (4 m) = 20 N
That's IF the force was in the same direction as the 4m of motion.
If the force was kind of slanted, then it had to be stronger, and
it had a component of 20N in the direction of the motion.
Prior to determining the
experimental design, a scientist typically forms a hypothesis. The answer is
letter B. this is to prepare the scientist, the possible outcome of their
research before the experimental design whether they are wrong or not.
This question can be solved using the concept of friction energy.
The thermal energy change is b "258.4 J".
The change in thermal energy will be equal to the friction energy produced during the motion of the box.

where,
μ = coefficient of kinetic friction = 0.4
f = force applied = 38 N
d = distance traveled by the box = 17 m
Therefore,

<u>E = 258.4 J</u>
Learn more about friction energy here:
brainly.com/question/1343045?referrer=searchResults
Answer:
The <em><u>n = 2 → n = 3</u></em> transition results in the absorption of the highest-energy photon.
Explanation:

Formula used for the radius of the
orbit will be,
where,
= energy of
orbit
n = number of orbit
Z = atomic number
Here: Z = 1 (hydrogen atom)
Energy of the first orbit in H atom .

Energy of the second orbit in H atom .

Energy of the third orbit in H atom .

Energy of the fifth orbit in H atom .

Energy of the sixth orbit in H atom .

Energy of the seventh orbit in H atom .

During an absorption of energy electron jumps from lower state to higher state.So, absorption will take place in :
1) n = 2 → n = 3
2) n= 5 → n = 6
Energy absorbed when: n = 2 → n = 3


Energy absorbed when: n = 5 → n = 6


1.89 eV > 0.166 eV
E> E'
So,the n = 2 → n = 3 transition results in the absorption of the highest-energy photon.
<span>Energy exists as light, heat, sound, mass, moving objects, gravity, fuel, chemicals, and electricity.</span>