Answer:
22.90 × 10⁸ kg
Explanation:
Given:
Diameter, d = 0.02 m
ωₙ = 0.95 rad/sec
Time period, T = 0.35 sec
Now, we know
T=
where, L is the length of the steel cable
g is the acceleration due to gravity
0.35=
or
L = 0.0304 m
Now,
The stiffness, K is given as:
K =
Where, A is the area
E is the elastic modulus of the steel = 2 × 10¹¹ N/m²
or
K =
or
K = 20.66 × 10⁸ N
Also,
Natural frequency, ωₙ =
or
mass, m =
or
mass, m =
mass, m = 22.90 × 10⁸ kg
Answer:
The power required to cool the water is 1.11Kw.
Hence the correct option is (b).
Explanation:
Power needed to cool down is equal to heat extract from the water.
Given:
Volume of water is 1 liter.
Initial temperature is 100C.
Final temperature is 20C.
Time is 5 minutes.
Take density of water as 100 kg/m3.
Specific heat of water is 4.186 kj/kgK.
Calculation:
Step1
Mass of the water is calculated as follows:
m=1kg
Step2
Amount of heat extraction is calculated as follows:
Q=334880 j.
Step3
Power to cool the water is calculated as follows:
P=1116.26W
or
P=1.11 Kw.
Thus, the power required to cool the water is 1.11Kw.
Hence the correct option is (b).