B an open system flow both
Answer:
2,4,5 are the answers
Explanation:
sky diver suit, helicopter and feather hAVE an external force pushing or floating them
Answer:
There is an arrow up for air resistance and an arrow down for gravity. The arrow up is longer than the arrow down.
Explanation:
The text of the problem says that the skydiver is slowing down: this means that he has an acceleration, which is directed opposite to the motion of the skydiver. Since the motion is downward, the acceleration must be upward.
There are two forces acting on the skydiver: the gravity (downward) and the air resistance (upward). According to Newton's second law:
F=ma
the acceleration has the same direction of the net force, so the net force must also be upward: therefore, the air resistance must be greater than the gravity, so the arrow up for air resistance is longer than the arrow down for gravity.
Answer:
The third choice: 
Explanation:
The cork is positively charged, therefore we know tat there must be excess of positively charged protons present.
The charge 
of a proton is
;
therefore, the number 
that makes up a charge of 
is
which is the 3rd choice.
Answer:
468449163762.0812 W
Explanation:
m = Mass = 
V = Volume =
r = Distance of sphere from isotropic point source of light = 0.5 m
R = Radius of sphere = 2 mm
= Density = 19 g/cm³
c = Speed of light = 
A = Area = 
I = Intensity = 
g = Acceleration due to gravity = 9.81 m/s²
Force due to radiation is given by
According to the question
The power required of the light source is 468449163762.0812 W
