I believe the correct answer would be zero. The work done in the truck is equal zero since the truck is not moving. Work by definition is the product of force and distance traveled due to the force. In this case, distance is zero giving us a zero work. Hope this helps.
Answer:
88.8 m/s= Speed of wave propagation in the required mode.(3 loops)
Explanation:
When there are 3 loops.
the total length = L = 3 λ /2
⇒ λ = 2 L / 3 = 2 ( 1.11 ) / 3 = 0.74 m
Velocity = v = f λ = (120)(0.74) = 88.8 m/s
The resolution of the angles measured (which is to 2d.p) is greater than the resolution that a normal protractor would show (no d.p)
e.g You can't really put a protractor down and say that's exactly 27.94 degrees, so something more accurate must've been used
Please find attached photograph for your answer.
