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:
Time period, 
Explanation:
Given that,
The quartz crystal used in an electric watch vibrates with a frequency of 32,768 Hz, f = 32768 Hz
We need to find the period of the crystal's motion. The relationship between the frequency and the time period is given by :
T is the time period of the crystal's motion.
Time period is given by :
So, the time period of the crystal's motion is 
. Hence, this is the required solution.
Answer: F = 1235 N
Explanation: Newton's Second Law of Motion describes the effect of mass and net force upon acceleration: 
Acceleration is the change of velocity in a period of time: 
Velocity of the car is in km/h. Transforming it in m/s:
v = 13 m/s
At the moment the car decelerates, acceleration is
a = 65 m/s²
Then, force will be
= 1235 N
The horizontal net force the straps of the restraint chair exerted on the child to hold her is 1235 newtons.
Answer:
Rotating the loop until it is perpendicular to the field
Explanation:
Current is induced in a conductor when there is a change in magnetic flux.
The strength of the induced current in a wire loop moving through a magnetic field can be increased or decreased by the following methods:
By increasing the strength of the magnetic field there will be increased in the induced current. If the strength of the magnetic field is decreased then there is a decrease in induced current.
By increasing the speed of the wire there will be increased in the induced current. When the speed of the wire is decreased then there is a decrease in induced current.
By increasing the number of turns of the coil the strength of the induced current can be increased. when there is less number of turns in coils then there is a decrease in induced current.
Rotating the loop until it is perpendicular to the field will not increase the current induced in a wire loop moving through a magnetic field.
Therefore, the option is (c) is correct.
