Answer:
A. It is always a positive force
Explanation:
Hooke's law describes the relation between an applied force and extension ability of an elastic material. The law states that provided the elastic limit, e, of a material is not exceeded, the force, F, applied is proportional to the extension, x, provided temperature is constant.
i.e F = - kx
where k is the constant of proportionality, and the minus sign implies that the force is a restoring force.
The applied force can either be compressing or stretching force.
Explanation:
It doesn't depends upon other.
It have it's own identity.
It's a lot easier to measure temperature than to measure the motion of component particles.
Answer: (a) Z-score are 1 and -1.2 for northern and southern regions, respectively.
Explanation: <u>Z-score</u> is how many standard deviations a data is from the population mean or how far a data point is from the mean.
The z-score is calculated by the following:

where
x is the data point
μ is population mean
σ is standard deviation
For the <u>northern</u> <u>region</u> birds:
μ = 10, σ = 3, x = 13

z = 1
The z-score for birds living in the northern region is 1, which means it is 1 standard deviation <em>above the mean</em>.
For the southern region:
μ = 16, σ = 2.5, x = 13

z = -1.2
The z-score for southern living birds is -1.2, meaning it is 1.2 standard deviations <em>below the mean</em>.
Heat because in a machine heat must come out to follow the law of conservation of energy
Answer:
W = 16.5 Kj
P = 49.9 Watt
E = 16471
Explanation:
m = 73.5kg
t = 5min 30sec = (5×60) + 30 = 330sec
each step = 16.6cm = 0.166m
h = 135×0.166 = 22.41 m
g = 10 m/s²
(i) W = F × s = W × h = mgh
W = 73.5×10×22.41 = 16471.35
W = 16.5 Kj
(ii) Power = workdone/time
P = 16471.35/330
P = 49.9 Watt
(iii) The energy burnt in this process = 16471