Since waves are moving, we define frequency as the number of waves that pass a given point in a specified unit of time. The unit commonly used is Hertz which is the number of wave cycles that pass a point in one second.
Answer:
17.27m/s
Explanation:
M1U1 + M2U2 = (M1+M2)V
(900x15) + (750 x 20) = (900+750)V
13500+15000 = (1650)V
28500 = 1650v
V = 28500/1650 = 17.27m/s
V = 17.27m/s
Answer:
Explanation:
a )
one kg of coal gives energy of 27 x 10⁶ J
75 kg of coal gives energy of 27 x 10⁶ x 75 J
So rate which energy is coming out of coal per second
= 27 x 10⁶ x 75 J
= 2025 x 10⁶ J /s
2025 million watts .
b ) energy output = 800 million watts
efficiency = (800 / 2025) x 100
= 39.5 % .
