Answer: Option (b) is the correct answer.
Explanation:
The given data is as follows.
F =
N
g = 9.8 m/s
radius =
=
= 15 cm = 0.15 m (as 1 m = 100 cm)
Formula to calculate depth is as follows.
F = 
or, h =
h =
= 751 m
Thus, we can conclude that the maximum depth in a lake to which the submarine can go without damaging the window is closest 750 m.
Answer:
C: equal to mg
Explanation:
in free-fall, gravity is always the net force on an object
Answer: c. the molecules with the highest energy evaporate first, lowering the temperature of the sample
Explanation:
The process by which liquid starts to change into vapor phase at any temperature is known as evaporation.
During evaporation , the molecules which possess higher energies escape from the upper layer into vapor phase. the molecules which escape draw energy from surroundings and thus decrease the energy of the surroundings and hence lead to decrease in temperature.
As temperature of the system is directly proportional to the energy of the system , thus decrease in energy leads to decrease in temperature.

K.E. = Kinetic energy
T = temperature
R= gas constant
Answer:
The following options are true based on the properties of electric field;
a) Electric field lines near positive point charges radiate outward.
b) The electric force acting on a point charge is proportional to the magnitude of the point charge.
d) In a uniform electric field, the field lines are straight, parallel, and uniformly spaced.
Explanation:
From option b) From coulomb's law F = Kq1q2r/r2