Answer:
Option (A) is correct.
Explanation:
A horizontal rope has a length of 5 m and a mass of 0.00145 kg. If a pulse occurs on this string, generating a wavelength of 0.6 m and a frequency of 120 Hz. The tension to which the string is subjected is
mass of string, m = 0.00145 kg
Frequency, f = 120 Hz
wavelength = 0.6 m
Speed = frequency x wavelength
speed = 120 x 0.6 = 72 m/s
Let the tension is T.
Use the formula

Option (A) is correct.
Answer:
20.62361 rad/s
489.81804 J
Explanation:
= Initial moment of inertia = 9.3 kgm²
= Final moment of inertia = 5.1 kgm²
= Initial angular speed = 1.8 rev/s
= Final angular speed
As the angular momentum of the system is conserved

The resulting angular speed of the platform is 20.62361 rad/s
Change in kinetic energy is given by

The change in kinetic energy of the system is 489.81804 J
As the work was done to move the weight in there was an increase in kinetic energy
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:
m = 77.75 g
Explanation:
Here we know that at equilibrium the temperature of the system will be 10 degree C
so heat given by hot latte = heat absorbed by the ice
now we have
heat given by latte = 


now heat absorbed by ice is given as



now by heat balance we have



Answer:
(a) 
(b) 5220 j
(c) 1740 watt
(d) 3446.66 watt
Explanation:
We have given mass m = 290 kg
Initial velocity u = 0 m/sec
Final velocity v = 6 m/sec
Time t = 3 sec
From first equation of motion
v = u+at
So 
(a) We know that force is given by
F = ma
So force will be 
(b) From second equation of motion we know that

We know that work done is given by
W = F s = 580×9 =5220 j
(c) Time is given as t = 3 sec
We know that power is given as

(d) Time t = 1.5 sec
So 