Answer:
(a) 0.33 second
(b) 6 cm/s
Explanation:
Frequency, f = 3 waves per second
wavelength, λ = 2 cm = 0.02 m
(a) The period of wave is defined as the time taken by the wave to complete one oscillation. It is the reciprocal of frequency.
T = 1 / f = 1 / 3 = 0.33 second
(b) the relation between wave velocity, frequency and wavelength is given by
v = f x λ
v = 3 x 0.02 = 0.06 m /s
v = 6 cm /s
Answer:
Velocity from second channel will be 1.6875 m/sec
Explanation:
We have given width of the channel , that is diameter of the channel 1 
= 12 m
So radius 
Speed through the channel 1 
Width , that is diameter of the channel 2 
So 
From continuity equation
So velocity from smaller channel will be 1.6875 m /sec
Answer:
<em>8hours 45minutes</em>
Explanation:
Amount of heat energy used up by the electric substance = heat gained by the water.
Amount of heat energy used up by the electric substance = Power * Time
heat gained by the water. = mcΔt
m is the mass of the water in kg
c is the specific heat capacity
Δt is the change in temperature
Given parameters
Power = 5kW = 5000W
mass of water m = 500kg
c = 4200J/kgC
Δt = 100°C - 25°C = 75°C
Required
Time taken
Substituting the given parameters into the formula
Pt = mcΔt
5000t = 500*4200*75
5000t = 157,500,000
Divide both sides by 5000
t = 157,500,000/5000
t = 31,500 secs
t = (31,500/3600)hrs
t = 8.75hours
t = 8hours 45minutes
<em>Hence it takes 8hours 45minutes to heat 500 kg of water in the tank from 25c to 100c</em>
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