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.
Answer:
Correct option : (c) period.
Explanation:
The time that is required for a vibrating object to complete one full cycle is called the time period. If f is the frequency of a wave, then the relation between the frequency and the time period is given by :

These are the characteristics of a wave. Some other characteristics are wavelength, amplitude, intensity etc. So, the correct option is (c) "period".
The correct option is (A) 2.5 m/s
Explanation:
Since,
v = fλ ---- (1)
where v = speed of the wave
f = frequency of the wave = 5 Hz
λ = wavelength of the wave = 0.5
Plug in the value in (1):
(1) => v = 5 * 0.5
v = 2.5 m/s
Average speed = total distance / total time
total distance = 40 + 20 = 60km
total time taken = 10 + 5 = 15 minutes
Average speed = 60/15 = 4km/min
<span>d. will fruit flies bred under different conditions mate?
Let's look at the possible choices and see which of them make any sense given the experiment.
a. do well-fed fruit flies make good pets?
Seems kinda silly, but if this were the question being asked, I suspect the experiment would have some fruit flies that were well fed as well as some fruit flies that were starved and would then compare how those 2 populations of fruit flies interacted with people. But that wasn't done, so it's unlikely this is the question being asked.
b. what kind of food do fruit flies prefer?
Each population of fruit flies weren't given a choice as to available foods. So their preferences didn't come into play about what they were allowed to eat. So this question is also unlikely.
c. how many species of fruit flies can mate with each other?
The scientist started with a single population and divided it into two sub groups. There doesn't seem to be a large number of species of different fruit flies here, so this is also an unlikely question.
d. will fruit flies bred under different conditions mate?
The scientist started with a single population of fruit flies and divided them into two groups. Each group was allowed to breed for many generations with a different food for each group (e.g. Allowed to breed under different conditions). After they were both well established, the groups were merged together and observed which ones mated. It looks like this question is being answered. So this is the correct solution.</span>