Wavelength = speed / frequency
(345 m/s) / (20,000 Hz) = 0.017 m
The sound wave would behave differently in a swimming pool than in his bedroom because sound waves travel faster in more dense mediums; such as water. The wave will travel faster in water, and slower in air.
Answer
given,
mass of the crate = 53 Kg
force applied by the worker = 180 N
Angle made with the horizontal = 35°
crate moves = 2.9 m
a) The work done equals the force in the direction of the displacement, times the displacement
W = F_x ×d
W = 180 cos 35° × 2.9
W = 427.6 J
b) A force that is perpendicular to the direction of the displacement does not do any work so work done by gravitational force is zero
c) Similarly for the normal force the work done will be zero.
d) Total work done by the crate is equal to 427.6 J
140 ? i’m guessing there doesn’t look like there’s much to the question
