Answer: Option 2
Explanation:
Option 1 is wrong because there are 2 protons and 2 neutrons in nucleus.
Option 3 is wrong because there are two electrons moving around nucleus.
Option 4 is wrong because electrons are negatively charged and are moving around the nucleus.
Option 5 is wrong because there equal amount of protons and electrons with 2 each.
Answer:
(a) The absolute pressure at the bottom of the freshwater lake is 395.3 kPa
(b) The force exerted by the water on the window is 36101.5 N
Explanation:
(a)
The absolute pressure is given by the formula

Where
is the absolute pressure
is the atmospheric pressure
is the density
is the acceleration due to gravity (Take
)
h is the height
From the question
h = 30.0 m
= 1.00 × 10³ kg/m³ = 1000 kg/m³
= 101.3 kPa = 101300 Pa
Using the formula
P = 101300 + (1000×9.8×30.0)
P = 101300 + 294000
P =395300 Pa
P = 395.3 kPa
Hence, the absolute pressure at the bottom of the freshwater lake is 395.3 kPa
(b)
For the force exerted
From
P = F/A
Where P is the pressure
F is the force
and A is the area
Then, F = P × A
Here, The area will be area of the window of the underwater vehicle.
Diameter of the circular window = 34.1 cm = 0.341 m
From Area = πD²/4
Then, A = π×(0.341)²/4 = 0.0913269 m²
Now,
From F = P × A
F = 395300 × 0.0913269
F = 36101.5 N
Hence, the force exerted by the water on the window is 36101.5 N
Answer:
-0.55m/s
Explanation:
Given that: For the boy
Weight = 745N
Velocity = +0.35 m/s
Mass of the boy = ?
g = 9.81m/s^2
W = mg
745 = m×9.81
m = 75.94kg
For the girl
Given that:
Weight = 477 N
g = 9.81m/s^2
m = ?
W = mg
477 = m×9.81m/s^2
m = 48.62kg
To solve for the v of the girl, the two has to add up
48.62kg×v + 75.94kg×+0.35 m/s = 0
48.62v + 26.579 = 0
48.62v = - 26.579
v = -26.579/48.62
v = -0.5466
v = -0.55m/s
Hence, the velocity of the girl is -0.55m/s.
The negative sign is as a result of the two of them moving is opposite direction.
Answer:
(A) The period of its rotation is 0.5 s (2) The frequency of its rotation is 2 Hz.
Explanation:
Given that,
a ball is spun around in circular motion such that it completes 50 rotations in 25 s.
(1). Let T be the period of its rotation. It can be calculated as follows :

(2). Let f be the frequency of its rotation. It can be defined as the number of rotations per unit time. So,

Hence, this is the required solution.