Answer:
B)The motion of water in an ocean current
Explanation:
With respect to measurements, a vector has both a magnitude and a direction. The first three examples (maximum height of a hill, air temperature, and rain accumulation) are magnitudes only. The fourth example (motion of water in an ocean current) is a vector, because it has a magnitude (speed) and a direction (with the current).
Answer:
Bottle opener works on a fulcrum.
Explanation:
A bottle opener is a second-class lever because the pivot point is at one end of the opener and the load is in the middle.
In a string of length L, the wavelength of the n-th harmonic of the standing wave produced in the string is given by:

The length of the string in this problem is L=3.5 m, therefore the wavelength of the 1st harmonic of the standing wave is:

The wavelength of the 2nd harmonic is:

The wavelength of the 4th harmonic is:

It is not possible to find any integer n such that
, therefore the correct options are A, B and D.
Seismic wave is the answer
Answer:
= 2630.6 N.m
Explanation:
(FR)x = ΣFx = -F4 = -407 N
(FR)y = ΣFy =-F1-F2 -F3 = -510 - 306 - 501 = -1317 N
(MR)B =ΣM + Σ(±Fd)
= MA + F1(d1 +d2) + F2d2 - F4d3
= 1504 + 510(0.880+1.11) +306(1.11) - 407(0.560)
= 2630.64 N.m (counterclockwise)