Answer:
a) 2Hz
b) 0.5seconds
c) 0.34m/s
Explanation:
a) Frequency is defined as the number of oscillations completed by a wave in one second.
If my finger is dipped into a pan of water twice each second, it means that my hand has made 2 oscillations through the water in one second. An oscillation is a to and fro movement of a particle, body or wave through a medium.
Based on the conclusion, the frequency of the waterwaves will be 2Hertz or 2cycles/sec.
2) Period T of a wave is defined as the time taken by a wave to complete one oscillation. It is the reciprocal of the frequency of a wave.
T = 1/F
Given frequency = 2Hertz
T = 1/2
T = 0.5seconds
Period of the water wave is 0.5seconds
c) speed of the wave v is expressed according to the relationship:
velocity = frequency × wavelength
Given:
Frequency = 2Hertz
Wavelength = 0.17m (Since it is the difference between two successive crest or trough of a wave)
Velocity = 2×0.17
Velocity = 0.34m/s
Answer:
2.866 x 10^8 J
Explanation:
Thermal conductivity, K = 0.040 W/m^2 k
Area of the wall, A = 470 m^2
Thickness, d = 17 cm = 0.17 m
difference in temperature, ΔT = 30° C
The rate of heat flow is H.
Time, t = 1 day = 1 x 24 x 60 x 60 second = 86400 second
By use of formula of heat flow


H = 2.866 x 10^8 J
Answer:
A.B = -38
Explanation:
A = 2i + 9j and B = -i - 4j.
So, A.B = (2i + 9j).(-i - 4j)
= 2i.(-i) + 2i.(-4j) + 9j.(-i) + 9j.(-4j)
= -2i.i - 8i.j - 9j.i - 36j.j
since i.i = 1, j.j = 1, i.j = 0 and j.i = 0, we have
A.B = -2(1) - 8(0) - 9(0) - 36(1)
A.B = -2 - 0 - 0 - 36
A.B = -38
OPTION C is the correct answer.
A = Delta v/Delta t
Delta v = 25 - 0 = 25
Delta t = 30
25/30 = 5/6 = 1.66 repeating