D. Speed and direction, this is because velocity is a vector quantity so has a magnitude and direction assigned to it because it is the rate of change of displacement.
If you write down the formula for friction, you will get an answer.
Ff = u * N Where N is a push down force that an object experiences.
u (mu) is a constant and has no units
It may not be accelerating and still experience friction. A is not correct.
Color and Density will not affect the frictional force. B is not so.
Buoyant forces are a different thing altogether. Generally friction has nothing to do with them. C is incorrect.
The last one is your answer. Technically mg should be the answer and not mass, but the second part is correct.
To solve this problem, use the ratio given by the total number of electrons or protons that exist as a function of the total charge, and inversely proportional to the value of the fundamental charge. The number of fundamental unit
that constitutes a charge of 40.0C can be calculated as

Here,
= Value of charge and it is the fundamental charge
Q = Total Charge
N = Total number of electron or protons
The number of fundamental units is calculated as follows


Therefore the number of fundamental charge units moved by lightning bolt is 
Answer: equal to 3 m/s
Explanation:
Speed of golf ball will be equal to 3 m/s because in Perfect Elastic Collision Energy is conserved .
So speed of golf ball will be same in order to Satisfy
Initial Kinetic Energy =Final Kinetic Energy
Considering Bowling ball remains at rest after collision other wise some energy will also be acquired by bowling ball which automatically decreases the amount of Kinetic Energy of golf ball resulting its speed to decrease by some extent.
So, the time needed before you hear the splash is approximately <u>2.06 s</u>.
<h3>Introduction</h3>
Hi ! In this question, I will help you. This question uses two principles, namely the time for an object to fall freely and the time for sound to propagate through air. When moving in free fall, the time required can be calculated by the following equation:



With the following condition :
- t = interval of the time (s)
- h = height or any other displacement at vertical line (m)
- g = acceleration of the gravity (m/s²)
Meanwhile, for sound propagation (without sound reflection), time propagates is the same as the quotient of distance by time. Or it can be formulated by :

With the following condition :
- t = interval of the time (s)
- s = shift or displacement (m)
- v = velocity (m/s)
<h3>Problem Solving</h3>
We know that :
- h = height or any other displacement at vertical line = 19.6 m
- g = acceleration of the gravity = 9.8 m/s²
- v = velocity = 343 m/s
What was asked :
= ... s
Step by step :
- Find the time when the object falls freely until it hits the water. Save value as





- Find the time when the sound propagate through air. Save value as




- Find the total time




<h3>Conclusion</h3>
So, the time needed before you hear the splash is approximately 2.06 s.