To get the solution you must need to draw a force triangle. Attach the head of the 60N north force arrow with the tail of the 60N east force arrow. The subsequent is the arrow connecting he tail and head of the two arrows.
You get a right angled triangle, and the resultant is (60^2 + 60^2) ^0.5 = 84.85 N or 85 N northeast.
The loudness<span> of a sound is linked to the size of the vibration which produces it. A big vibration makes a louder sound. Scientists use the word '</span>amplitude<span>' for the size of waves. For waves on water, it is easy to measure the </span>amplitude<span>.</span>
F=ma
Therefore the net force = 1000kg × 2 metres per second per second
So F=2000 N
I., II., and IV. are examples of acceleration. III. isn't.