Answer
given,
height of Alpe d'Huez = 1100-m
time = 37.5 min
mass of the rider and his bike = 65 Kg
the metabolic power to ride = 700 W
U = m g y
U = 65 x 9.8 x 1100
U = 700700 J
since efficiency is 25%
b) 
P = 1245.68 W
Around 80 percent of the mass of the universe is made up material known as "Dark matter". It does not emit light or energy but the influence of it can be detected or observed gravitationally. Motions of stars and galaxy tell us how much mater there is, but somehow the speed of rotation of galaxy does not add up to its mass alone, there is a certain amount of matter really not accounted for. Dark matter maybe made up of non-baryonic matter, or perhaps what scientist called the WIMPS or (weakly interacting massive particles.)
Mutualism is a long-term relationship where two organisms interact in such a way that both of them benefits from that relationship.
For example, there is a relationship between a bird called "oxpecker", and a rhino. While the bird eats the harmful bugs (eg. tick) on the rhino's skin and relieves its hunger; the rhino gets rid of the bugs that harm it.
Answer:
Weight is a force.
Explanation:
Force acting on an object is defined in terms of mass and its acceleration. Its mathematical force is given by
F = ma
Weight of an object is force that the Earth exerts on an object. It can be given by the formula as follows :
W = mg
g is acceleration due to gravity on the surface of earth
Hence, the correct option is (d).
T=s/v=>t=1500/1,5=1000s
1,5km=1500m
